Unfied Threads (UNC/UNF/UNEF): Dimensions & Formulas

Table Of Contents

List of Charts
Overview
Designation
Possible Combinations (Diameter/Pitch)
Basic Thread Dimensions (UNC, UNF & UNEF)
limits of Thread Dimensions (UNC, UNF & UNEF)

List of Charts

* Easy access to all the data charts that appear on this page

Overview

The Unified Thread Standard (UTS) defines a 60° thread form in Inch dimensions as described in the ASME B1.1 standard. It is the North American equivalent of the ISO metric thread system. The UTS serves as the leading standard for bolts, nuts, and a wide variety of other threaded fasteners used in the USA and Canada. However, in recent years the metric thread standard is becoming more common.
The standard defines diameter and pitch combinations along with allowances, tolerances, and designations. It has the same 60° profile as the ISO metric screw thread, but the basic dimensions of each UTS thread were chosen as an inch fraction rather than a millimeter value.

Designation

Basic designation syntax:

Nominal Diameter in Inch Fraction
Pitch in TPI
Series: UNC / UNF / UNEF / UN
Class: 1A, 2A, 3A, 1B, 2B or 3B.

Diameter:

From 1/4″ and above the diameters are given in inch fractions. For example 1/4″, 3/4″, 1 1/4″.
Below 1/4″ the diameters are given by a series of numbers from #0 to #12. Each “number” describes an arbitrary diameter as shown in the below table.
It is also allowed to denote the diameters with a decimal value. For example 0.250 (1/4″), 0.4375 (7/16″), etc.

Standard Diameter numbers below 1/4″

Diameter Number	#0	#1	#2	#3	#4	#5	#6	#8	#10	#12
Diameter (Inch)	0.006	0.0073	0.0086	0.0099	0.112	0.125	0.138	0.164	0.19	0.216
Diameter (mm)	1.524	1.8542	2.1844	2.5146	2.8448	3.175	3.5052	4.1656	4.8260	5.4864

Pitch:

By default, the pitch is given in TPI. For example, 1/4-20 means a thread with a pitch of 20 TPI (1/20=0.05″).
It is also allowed to denote the pitch by distance. For example, 1/4-0.05P means a thread with a pitch of 0.05″ (same as 20 TPI).

Series:

In most cases, the series will be UNC, UNF, or UNEF (Coarse, Fine, or Extra fine pitch).
ASTM B1.1, also defines several constant pitch series. These are denoted by ##-UN. For example, 12-UN or 8-UN. The pitch remains the same for the whole diameter range in these series. However, they are much less popular.

Class:

The class is defined by a two-character code.
- The first character is a digit between 1 and 3. 1=Tight fit, 2=Medium fit, and 3=Loose fit.
- The second character is a letter. A=External thread and B=Internal thread.
- For a detailed explanation of classes, read the dedicated section below.

Additional Parameters:

Direction: By default, the thread is right-hand. For a left-hand thread, add the suffix -LH.
Number of Starts: By default, all threads have a single start. Thus the lead equals the pitch. For a multiple-start thread, the lead is also indicated. For example: 3/4– 0.0625P – 0.1875L UNF denotes a 3/4″ UNF thread with 3 starts. (0.1875/0.0625=3)

Designation Examples of Unified Threads

Designation	Series	Internal or External	Nominal Daimeter	TPI	Pitch	Lead	Class	Number of Starts	Thread Direction
#8-32 UNC	UNC	Undefined	0.164"	32	0.03125"	Same as Pitch	Undefined	1	Right Hand
1/4 -28 UNF-2A	UNF	External	0.25"	28	0.0357"	Same as Pitch	2A	1	Right Hand
3/4-20 UNEF-3B	UNEF	Internal	0.75"	20	0.05"	Same as Pitch	3B	1	Right Hand
1-12 UN-1A	Constant Pitch 12 TPI	External	1"	12	0.0833"	Same as Pitch	1A	1	Right Hand
3/4– 0.0625P – 0.1875L UNF-2A	UNF	External	0.75"	16	0.0625"	0.1875"	2A	3	Right Hand
1/4 -28 UNF-2A-LH	UNF	External	0.25"	28	0.0357"	Same as Pitch	2A	1	Left Hand

Possible Combinations (Diameter/Pitch)

The below charts show all the possible thread combinations that are defined in ASTM B1.1

UNC– Unified Inch Coarse Thread Series
UNF – Unified Inch Fine Thread Series
UNEF – Unified Inch Extra Fine Thread Series
##-UN – Unified Inch Constant PitchThread Series
Click to get the Full Thread Data-Sheet for a specific combination

Possible Combinations for 1/16″ – 1/4″

Possible Combinations for 5/16″ – 1 1/2″

Possible Combinations for 1 9/16″ – 6″

Basic Thread Dimensions (UNC, UNF & UNEF)

The basic dimensions are nominal dimensions of a unified thread profile without allowance and tolerances (The thread class defines that). They are based on standard ASTM B1.1. The basic dimensions can be used for design. However, for manufacturing and machining, you need the allowable rage of each dimension. This data can be found in the standard or in the Limits and Dimensions section below. All the basic dimensions are derived from simple formulas based on the thread’s nominal diameter and pitch.

Symbols

List of symbols used in charts and formulas of Unified Inch Threads

Symbol	Explanation
Basic Parameters - Diameters and Pitch
D	Major (Basic) diameter of internal thread
D₁	Minor diameter of internal thread
D₂	Pitch diameter of internal thread
D₃	Major diameter, rounded root, internal thread
d	Major (Basic) diameter of external thread
d₁	Minor diameter of external thread
d₂	Pitch diameter of external thread
d₃	Major diameter, rounded root, internal thread
n	Number of threds per Inch (TPI)
P	Pitch (Distance)
L	Lead
Height Parameters
H	Height of fundamental triangle
h_s	Thread height - External thread
h_as	Thread addendum - External thread
h_n	Thread height - Internal thread
h_an	Thread addendum - Internal thread
Length Parameters
LE	Length of thread engagement
L_ts	Length of complete external thread
L_tn	Length of complete internal thread
Allowance, Deviation, and Tolerances
T_D1	Tolerance for D₁
T_D2	Tolerance for D₂
T_d	Tolerance for d
T_d2	Tolerance for d₂
es	Allowance for external thread
Root / Creast Parameters
F_cs	Flat crest width of external thread
F_rs	Flat root width of external thread
F_cs	Flat crest width of internal thread
F_cs	Flat root width of internal thread

The below video provides a short explanation of the threading terms

Formulas for basic dimensions

External Thread

\( \large d=\text{Basic Diameter} \)
\( \large P=\frac{1}{TPI} \)
\( \large H=\frac{\sqrt{3}}{2}\times{P} = 0.866025404\times{P} \)
\( \large h_s=\frac{5}{8}\times{H} \)
\( \large h_{as}=\frac{3}{8}\times{H}\)
\( \large d_2=d-{2}\times{h_{as}} \)
\( \large d_1=d-{2}\times{h_s}\)
\( \large F_{cs}=\frac{P}{8}\)
\( \large F_{rs}=\frac{P}{4}\)

internal thread

\( \large D=\text{Basic Diameter} \)
\( \large P=\frac{1}{TPI} \)
\( \large H=\frac{\sqrt{3}}{2}\times{P} = 0.866025404\times{P} \)
\( \large h_n=\frac{5}{8}\times{H} \)
\( \large h_{an}=\frac{1}{4}\times{H}\)
\( \large D_1=D-{2}\times{h_n}\)
\( \large D_2=D1+{2}\times{h_{an}}\)
\( \large F_{rn}=\frac{P}{8}\)
\( \large F_{cn}=\frac{P}{4}\)

Unified Inch Threads Dimensions Charts

UNC Series Basic Dimensions chart

Click the Thread Link to get the Full Thread Data for all classes in Inch and Metric units.

All dimensions are in inches. To view Metric translation click the Thread Link

Thread	Nominal Diameter	TPI	Pitch	Pitch Diameter	Thread Height	Cres/Root Width	Tap Drill	Lead Angle
#1 - 64 UNC	0.0730	64	0.016	0.063	0.008	0.004	0.059	4.52
#2 - 56 UNC	0.0860	56	0.018	0.074	0.010	0.004	0.070	4.37
#3 - 48 UNC	0.0990	48	0.021	0.085	0.011	0.005	0.080	4.44
#4 - 40 UNC	0.1120	40	0.025	0.096	0.014	0.006	0.089	4.75
#5 - 40 UNC	0.1250	40	0.025	0.109	0.014	0.006	0.102	4.18
#6 - 32 UNC	0.1380	32	0.031	0.118	0.017	0.008	0.110	4.83
#8 - 32 UNC	0.1640	32	0.031	0.144	0.017	0.008	0.136	3.96
#10 - 24 UNC	0.1900	24	0.042	0.163	0.023	0.010	0.152	4.65
#12 - 24 UNC	0.2160	24	0.042	0.189	0.023	0.010	0.178	4.02
1/4 - 20 UNC	0.2500	20	0.050	0.218	0.027	0.013	0.205	4.18
5/16 - 18 UNC	0.3120	18	0.056	0.276	0.030	0.014	0.261	3.67
3/8 - 16 UNC	0.3750	16	0.063	0.334	0.034	0.016	0.318	3.40
7/16 - 14 UNC	0.4370	14	0.071	0.391	0.039	0.018	0.372	3.33
1/2 - 13 UNC	0.5000	13	0.077	0.450	0.042	0.019	0.430	3.11
9/16 - 12 UNC	0.5620	12	0.083	0.508	0.045	0.021	0.486	2.99
5/8 - 11 UNC	0.6250	11	0.091	0.566	0.049	0.023	0.542	2.93
3/4 - 10 UNC	0.7500	10	0.100	0.685	0.054	0.025	0.659	2.66
7/8 - 9 UNC	0.8750	9	0.111	0.803	0.060	0.028	0.774	2.52
1 - 8 UNC	1.0000	8	0.125	0.919	0.068	0.031	0.886	2.48
1 1/8 - 7 UNC	1.1250	7	0.143	1.032	0.077	0.036	-99	2.52
1 1/4 - 7 UNC	1.2500	7	0.143	1.157	0.077	0.036	-99	2.25
1 3/8 - 6 UNC	1.3750	6	0.167	1.267	0.090	0.042	-99	2.40
1 1/2 - 6 UNC	1.5000	6	0.167	1.392	0.090	0.042	-99	2.18
1 3/4 - 5 UNC	1.7500	5	0.200	1.620	0.108	0.050	-99	2.25
2 - 4.5 UNC	2.0000	4	0.222	1.856	0.120	0.056	-99	2.18
2 1/4 - 4.5 UNC	2.2500	4	0.222	2.106	0.120	0.056	-99	1.92
2 1/2 - 4 UNC	2.5000	4	0.250	2.338	0.135	0.063	-99	1.95
2 3/4 - 4 UNC	2.7500	4	0.250	2.588	0.135	0.063	-99	1.76
3 - 4 UNC	3.0000	4	0.250	2.838	0.135	0.063	-99	1.61
3 1/4 - 4 UNC	3.2500	4	0.250	3.088	0.135	0.063	-99	1.48
3 1/2 - 4 UNC	3.5000	4	0.250	3.338	0.135	0.063	-99	1.37
3 3/4 - 4 UNC	3.7500	4	0.250	3.588	0.135	0.063	-99	1.27
4 - 4 UNC	4.0000	4	0.250	3.838	0.135	0.063	-99	1.19

UNF Series Basic Dimensions chart

Click the Thread Link to get the Full Thread Data for all classes in Inch and Metric units.

All dimensions are in inches. To view Metric translation click the Thread Link

Thread	Nominal Diameter	TPI	Pitch	Pitch Diameter	Thread Height	Cres/Root Width	Tap Drill	Lead Angle
#0 - 80 UNF	0.0600	80	0.013	0.052	0.007	0.003	0.049	4.39
#1 - 72 UNF	0.0730	72	0.014	0.064	0.008	0.003	0.060	3.95
#2 - 64 UNF	0.0860	64	0.016	0.076	0.008	0.004	0.072	3.75
#3 - 56 UNF	0.0990	56	0.018	0.087	0.010	0.004	0.083	3.72
#4 - 48 UNF	0.1120	48	0.021	0.098	0.011	0.005	0.093	3.85
#5 - 44 UNF	0.1250	44	0.023	0.110	0.012	0.006	0.104	3.75
#6 - 40 UNF	0.1380	40	0.025	0.122	0.014	0.006	0.115	3.74
#8 - 36 UNF	0.1640	36	0.028	0.146	0.015	0.007	0.139	3.47
#10 - 32 UNF	0.1900	32	0.031	0.170	0.017	0.008	0.162	3.35
#12 - 28 UNF	0.2160	28	0.036	0.193	0.019	0.009	0.184	3.37
1/4 - 28 UNF	0.2500	28	0.036	0.227	0.019	0.009	0.218	2.87
5/16 - 24 UNF	0.3120	24	0.042	0.285	0.023	0.010	0.274	2.67
3/8 - 24 UNF	0.3750	24	0.042	0.348	0.023	0.010	0.337	2.18
7/16 - 20 UNF	0.4370	20	0.050	0.405	0.027	0.013	0.392	2.25
1/2 - 20 UNF	0.5000	20	0.050	0.468	0.027	0.013	0.455	1.95
9/16 - 18 UNF	0.5620	18	0.056	0.526	0.030	0.014	0.511	1.93
5/8 - 18 UNF	0.6250	18	0.056	0.589	0.030	0.014	0.574	1.72
3/4 - 16 UNF	0.7500	16	0.063	0.709	0.034	0.016	0.693	1.61
7/8 - 14 UNF	0.8750	14	0.071	0.829	0.039	0.018	0.810	1.57
1 - 12 UNF	1.0000	12	0.083	0.946	0.045	0.021	0.924	1.61
1 1/8 - 12 UNF	1.1250	12	0.083	1.071	0.045	0.021	-99	1.42
1 1/4 - 12 UNF	1.2500	12	0.083	1.196	0.045	0.021	-99	1.27
1 3/8 - 12 UNF	1.3750	12	0.083	1.321	0.045	0.021	-99	1.15
1 1/2 - 12 UNF	1.5000	12	0.083	1.446	0.045	0.021	-99	1.05

UNEF Series Basic Dimensions chart

Click the Thread Link to get the Full Thread Data for all classes in Inch and Metric units.

All dimensions are in inches. To view Metric translation click the Thread Link

Thread	Nominal Diameter	TPI	Pitch	Pitch Diameter	Thread Height	Cres/Root Width	Tap Drill	Lead Angle
#12 - 32 UNEF	0.2160	32	0.031	0.196	0.017	0.008	0.188	2.91
1/4 - 32 UNEF	0.2500	32	0.031	0.230	0.017	0.008	0.222	2.48
5/16 - 32 UNEF	0.3120	32	0.031	0.292	0.017	0.008	0.284	1.95
3/8 - 32 UNEF	0.3750	32	0.031	0.355	0.017	0.008	0.347	1.61
7/16 - 28 UNEF	0.4370	28	0.036	0.414	0.019	0.009	0.405	1.57
1/2 - 28 UNEF	0.5000	28	0.036	0.477	0.019	0.009	0.468	1.37
9/16 - 24 UNEF	0.5620	24	0.042	0.535	0.023	0.010	0.524	1.42
5/8 - 24 UNEF	0.6250	24	0.042	0.598	0.023	0.010	0.587	1.27
11/16 - 24 UNEF	0.6870	24	0.042	0.660	0.023	0.010	0.649	1.15
3/4 - 20 UNEF	0.7500	20	0.050	0.718	0.027	0.013	0.705	1.27
13/16 - 20 UNEF	0.8120	20	0.050	0.780	0.027	0.013	0.767	1.17
7/8 - 20 UNEF	0.8750	20	0.050	0.843	0.027	0.013	0.830	1.08
15/16 - 20 UNEF	0.9370	20	0.050	0.905	0.027	0.013	0.892	1.01
1 - 20 UNEF	1.0000	20	0.050	0.968	0.027	0.013	0.955	0.94
1 1/16 - 18 UNEF	1.0620	18	0.056	1.026	0.030	0.014	-99	0.99
1 1/8 - 18 UNEF	1.1250	18	0.056	1.089	0.030	0.014	-99	0.93
1 3/16 - 18 UNEF	1.1870	18	0.056	1.151	0.030	0.014	-99	0.88
1 1/4 - 18 UNEF	1.2500	18	0.056	1.214	0.030	0.014	-99	0.83
1 5/16 - 18 UNEF	1.3120	18	0.056	1.276	0.030	0.014	-99	0.79
1 3/8 - 18 UNEF	1.3750	18	0.056	1.339	0.030	0.014	-99	0.76
1 7/16 - 18 UNEF	1.4370	18	0.056	1.401	0.030	0.014	-99	0.72
1 1/2 - 18 UNEF	1.5000	18	0.056	1.464	0.030	0.014	-99	0.69
1 9/16 - 18 UNEF	1.5620	18	0.056	1.526	0.030	0.014	-99	0.66
1 5/8 - 18 UNEF	1.6250	18	0.056	1.589	0.030	0.014	-99	0.64
1 11/16 - 18 UNEF	1.6870	18	0.056	1.651	0.030	0.014	-99	0.61

UN Constant Pitch Series Basic Dimensions chart

Click the Thread Link to get the Full Thread Data for all classes in Inch and Metric units.

All dimensions are in inches. To view Metric translation click the Thread Link

Thread	Nominal Diameter	TPI	Pitch	Pitch Diameter	Thread Height	Cres/Root Width	Tap Drill	Lead Angle
#6 - 32 32-UN	0.1380	32	0.031	0.118	0.017	0.008	0.110	4.83
#8 - 32 32-UN	0.1640	32	0.031	0.144	0.017	0.008	0.136	3.96
#10 - 32 32-UN	0.1900	32	0.031	0.170	0.017	0.008	0.162	3.35
#12 - 32 32-UN	0.2160	32	0.031	0.196	0.017	0.008	0.188	2.91
1/4 - 32 32-UN	0.2500	32	0.031	0.230	0.017	0.008	0.222	2.48
5/16 - 32 32-UN	0.3120	32	0.031	0.292	0.017	0.008	0.284	1.95
3/8 - 32 32-UN	0.3750	32	0.031	0.355	0.017	0.008	0.347	1.61
7/16 - 32 32-UN	0.4370	32	0.031	0.417	0.017	0.008	0.409	1.37
1/2 - 32 32-UN	0.5000	32	0.031	0.480	0.017	0.008	0.472	1.19
9/16 - 32 32-UN	0.5620	32	0.031	0.542	0.017	0.008	0.534	1.05
5/8 - 32 32-UN	0.6250	32	0.031	0.605	0.017	0.008	0.597	0.94
11/16 - 32 32-UN	0.6870	32	0.031	0.667	0.017	0.008	0.659	0.85
3/4 - 32 32-UN	0.7500	32	0.031	0.730	0.017	0.008	0.722	0.78
13/16 - 32 32-UN	0.8120	32	0.031	0.792	0.017	0.008	0.784	0.72
7/8 - 32 32-UN	0.8750	32	0.031	0.855	0.017	0.008	0.847	0.67
15/16 - 32 32-UN	0.9370	32	0.031	0.917	0.017	0.008	0.909	0.62
1 - 32 32-UN	1.0000	32	0.031	0.980	0.017	0.008	0.972	0.58
#12 - 28 28-UN	0.2160	28	0.036	0.193	0.019	0.009	0.184	3.37
1/4 - 28 28-UN	0.2500	28	0.036	0.227	0.019	0.009	0.218	2.87
5/16 - 28 28-UN	0.3120	28	0.036	0.289	0.019	0.009	0.280	2.25
3/8 - 28 28-UN	0.3750	28	0.036	0.352	0.019	0.009	0.343	1.85
7/16 - 28 28-UN	0.4370	28	0.036	0.414	0.019	0.009	0.405	1.57
1/2 - 28 28-UN	0.5000	28	0.036	0.477	0.019	0.009	0.468	1.37
9/16 - 28 28-UN	0.5620	28	0.036	0.539	0.019	0.009	0.530	1.21
5/8 - 28 28-UN	0.6250	28	0.036	0.602	0.019	0.009	0.593	1.08
11/16 - 28 28-UN	0.6870	28	0.036	0.664	0.019	0.009	0.655	0.98
3/4 - 28 28-UN	0.7500	28	0.036	0.727	0.019	0.009	0.718	0.90
13/16 - 28 28-UN	0.8120	28	0.036	0.789	0.019	0.009	0.780	0.83
7/8 - 28 28-UN	0.8750	28	0.036	0.852	0.019	0.009	0.843	0.76
15/16 - 28 28-UN	0.9370	28	0.036	0.914	0.019	0.009	0.905	0.71
1 - 28 28-UN	1.0000	28	0.036	0.977	0.019	0.009	0.968	0.67
1 1/16 - 28 28-UN	1.0620	28	0.036	1.039	0.019	0.009	-99	0.63
1 1/8 - 28 28-UN	1.1250	28	0.036	1.102	0.019	0.009	-99	0.59
1 3/16 - 28 28-UN	1.1870	28	0.036	1.164	0.019	0.009	-99	0.56
1 1/4 - 28 28-UN	1.2500	28	0.036	1.227	0.019	0.009	-99	0.53
1 5/16 - 28 28-UN	1.3120	28	0.036	1.289	0.019	0.009	-99	0.51
1 3/8 - 28 28-UN	1.3750	28	0.036	1.352	0.019	0.009	-99	0.48
1 7/16 - 28 28-UN	1.4370	28	0.036	1.414	0.019	0.009	-99	0.46
1 1/2 - 28 28-UN	1.5000	28	0.036	1.477	0.019	0.009	-99	0.44
1/4 - 20 20-UN	0.2500	20	0.050	0.218	0.027	0.013	0.205	4.18
5/16 - 20 20-UN	0.3120	20	0.050	0.280	0.027	0.013	0.267	3.26
3/8 - 20 20-UN	0.3750	20	0.050	0.343	0.027	0.013	0.330	2.66
7/16 - 20 20-UN	0.4370	20	0.050	0.405	0.027	0.013	0.392	2.25
1/2 - 20 20-UN	0.5000	20	0.050	0.468	0.027	0.013	0.455	1.95
9/16 - 20 20-UN	0.5620	20	0.050	0.530	0.027	0.013	0.517	1.72
5/8 - 20 20-UN	0.6250	20	0.050	0.593	0.027	0.013	0.580	1.54
11/16 - 20 20-UN	0.6870	20	0.050	0.655	0.027	0.013	0.642	1.39
3/4 - 20 20-UN	0.7500	20	0.050	0.718	0.027	0.013	0.705	1.27
13/16 - 20 20-UN	0.8120	20	0.050	0.780	0.027	0.013	0.767	1.17
7/8 - 20 20-UN	0.8750	20	0.050	0.843	0.027	0.013	0.830	1.08
15/16 - 20 20-UN	0.9370	20	0.050	0.905	0.027	0.013	0.892	1.01
1 - 20 20-UN	1.0000	20	0.050	0.968	0.027	0.013	0.955	0.94
1 1/16 - 20 20-UN	1.0620	20	0.050	1.030	0.027	0.013	-99	0.89
1 1/8 - 20 20-UN	1.1250	20	0.050	1.093	0.027	0.013	-99	0.83
1 3/16 - 20 20-UN	1.1870	20	0.050	1.155	0.027	0.013	-99	0.79
1 1/4 - 20 20-UN	1.2500	20	0.050	1.218	0.027	0.013	-99	0.75
1 5/16 - 20 20-UN	1.3120	20	0.050	1.280	0.027	0.013	-99	0.71
1 3/8 - 20 20-UN	1.3750	20	0.050	1.343	0.027	0.013	-99	0.68
1 7/16 - 20 20-UN	1.4370	20	0.050	1.405	0.027	0.013	-99	0.65
1 1/2 - 20 20-UN	1.5000	20	0.050	1.468	0.027	0.013	-99	0.62
1 9/16 - 20 20-UN	1.5620	20	0.050	1.530	0.027	0.013	-99	0.60
1 5/8 - 20 20-UN	1.6250	20	0.050	1.593	0.027	0.013	-99	0.57
1 11/16 - 20 20-UN	1.6870	20	0.050	1.655	0.027	0.013	-99	0.55
1 3/4 - 20 20-UN	1.7500	20	0.050	1.718	0.027	0.013	-99	0.53
1 13/16 - 20 20-UN	1.8120	20	0.050	1.780	0.027	0.013	-99	0.51
1 7/8 - 20 20-UN	1.8750	20	0.050	1.843	0.027	0.013	-99	0.49
1 15/16 - 20 20-UN	1.9370	20	0.050	1.905	0.027	0.013	-99	0.48
2 - 20 20-UN	2.0000	20	0.050	1.968	0.027	0.013	-99	0.46
2 1/8 - 20 20-UN	2.1250	20	0.050	2.093	0.027	0.013	-99	0.44
2 1/4 - 20 20-UN	2.2500	20	0.050	2.218	0.027	0.013	-99	0.41
2 3/8 - 20 20-UN	2.3750	20	0.050	2.343	0.027	0.013	-99	0.39
2 1/2 - 20 20-UN	2.5000	20	0.050	2.468	0.027	0.013	-99	0.37
2 5/8 - 20 20-UN	2.6250	20	0.050	2.593	0.027	0.013	-99	0.35
2 3/4 - 20 20-UN	2.7500	20	0.050	2.718	0.027	0.013	-99	0.34
2 7/8 - 20 20-UN	2.8750	20	0.050	2.843	0.027	0.013	-99	0.32
3 - 20 20-UN	3.0000	20	0.050	2.968	0.027	0.013	-99	0.31
4 5/8 - 20-UN	4.6250	20	0.050	4.593	0.027	0.013	-99	0.20
3/8 - 16 16-UN	0.3750	16	0.063	0.334	0.034	0.016	0.318	3.40
7/16 - 16 16-UN	0.4370	16	0.063	0.396	0.034	0.016	0.380	2.87
1/2 - 16 16-UN	0.5000	16	0.063	0.459	0.034	0.016	0.443	2.48
9/16 - 16 16-UN	0.5620	16	0.063	0.521	0.034	0.016	0.505	2.19
5/8 - 16 16-UN	0.6250	16	0.063	0.584	0.034	0.016	0.568	1.95
11/16 - 16 16-UN	0.6870	16	0.063	0.646	0.034	0.016	0.630	1.76
3/4 - 16 16-UN	0.7500	16	0.063	0.709	0.034	0.016	0.693	1.61
13/16 - 16 16-UN	0.8120	16	0.063	0.771	0.034	0.016	0.755	1.48
7/8 - 16 16-UN	0.8750	16	0.063	0.834	0.034	0.016	0.818	1.37
15/16 - 16 16-UN	0.9370	16	0.063	0.896	0.034	0.016	0.880	1.27
1 - 16 16-UN	1.0000	16	0.063	0.959	0.034	0.016	0.943	1.19
1 1/16 - 16 16-UN	1.0620	16	0.063	1.021	0.034	0.016	-99	1.12
1 1/8 - 16 16-UN	1.1250	16	0.063	1.084	0.034	0.016	-99	1.05
1 3/16 - 16 16-UN	1.1870	16	0.063	1.146	0.034	0.016	-99	0.99
1 1/4 - 16 16-UN	1.2500	16	0.063	1.209	0.034	0.016	-99	0.94
1 5/16 - 16 16-UN	1.3120	16	0.063	1.271	0.034	0.016	-99	0.90
1 3/8 - 16 16-UN	1.3750	16	0.063	1.334	0.034	0.016	-99	0.85
1 7/16 - 16 16-UN	1.4370	16	0.063	1.396	0.034	0.016	-99	0.82
1 1/2 - 16 16-UN	1.5000	16	0.063	1.459	0.034	0.016	-99	0.78
1 9/16 - 16 16-UN	1.5620	16	0.063	1.521	0.034	0.016	-99	0.75
1 5/8 - 16 16-UN	1.6250	16	0.063	1.584	0.034	0.016	-99	0.72
1 11/16 - 16 16-UN	1.6870	16	0.063	1.646	0.034	0.016	-99	0.69
1 3/4 - 16 16-UN	1.7500	16	0.063	1.709	0.034	0.016	-99	0.67
1 13/16 - 16 16-UN	1.8120	16	0.063	1.771	0.034	0.016	-99	0.64
1 7/8 - 16 16-UN	1.8750	16	0.063	1.834	0.034	0.016	-99	0.62
1 15/16 - 16 16-UN	1.9370	16	0.063	1.896	0.034	0.016	-99	0.60
2 - 16 16-UN	2.0000	16	0.063	1.959	0.034	0.016	-99	0.58
2 1/8 - 16 16-UN	2.1250	16	0.063	2.084	0.034	0.016	-99	0.55
2 1/4 - 16 16-UN	2.2500	16	0.063	2.209	0.034	0.016	-99	0.52
2 3/8 - 16 16-UN	2.3750	16	0.063	2.334	0.034	0.016	-99	0.49
2 1/2 - 16 16-UN	2.5000	16	0.063	2.459	0.034	0.016	-99	0.46
2 5/8 - 16 16-UN	2.6250	16	0.063	2.584	0.034	0.016	-99	0.44
2 3/4 - 16 16-UN	2.7500	16	0.063	2.709	0.034	0.016	-99	0.42
2 7/8 - 16 16-UN	2.8750	16	0.063	2.834	0.034	0.016	-99	0.40
3 - 16 16-UN	3.0000	16	0.063	2.959	0.034	0.016	-99	0.39
3 1/8 - 16 16-UN	3.1250	16	0.063	3.084	0.034	0.016	-99	0.37
3 1/4 - 16 16-UN	3.2500	16	0.063	3.209	0.034	0.016	-99	0.36
3 3/8 - 16 16-UN	3.3750	16	0.063	3.334	0.034	0.016	-99	0.34
3 1/2 - 16 16-UN	3.5000	16	0.063	3.459	0.034	0.016	-99	0.33
3 5/8 - 16 16-UN	3.6250	16	0.063	3.584	0.034	0.016	-99	0.32
3 3/4 - 16 16-UN	3.7500	16	0.063	3.709	0.034	0.016	-99	0.31
3 7/8 - 16 16-UN	3.8750	16	0.063	3.834	0.034	0.016	-99	0.30
4 - 16 16-UN	4.0000	16	0.063	3.959	0.034	0.016	-99	0.29
4 1/8 - 16 16-UN	4.1250	16	0.063	4.084	0.034	0.016	-99	0.28
4 1/4 - 16 16-UN	4.2500	16	0.063	4.209	0.034	0.016	-99	0.27
4 3/8 - 16 16-UN	4.3750	16	0.063	4.334	0.034	0.016	-99	0.26
4 1/2 - 16 16-UN	4.5000	16	0.063	4.459	0.034	0.016	-99	0.26
4 5/8 - 16 16-UN	4.6250	16	0.063	4.584	0.034	0.016	-99	0.25
4 3/4 - 16 16-UN	4.7500	16	0.063	4.709	0.034	0.016	-99	0.24
4 7/8 - 16 16-UN	4.8750	16	0.063	4.834	0.034	0.016	-99	0.24
5 - 16 16-UN	5.0000	16	0.063	4.959	0.034	0.016	-99	0.23
5 1/8 - 16 16-UN	5.1250	16	0.063	5.084	0.034	0.016	-99	0.22
5 1/4 - 16 16-UN	5.2500	16	0.063	5.209	0.034	0.016	-99	0.22
5 3/8 - 16 16-UN	5.3750	16	0.063	5.334	0.034	0.016	-99	0.21
5 1/2 - 16 16-UN	5.5000	16	0.063	5.459	0.034	0.016	-99	0.21
5 5/8 - 16 16-UN	5.6250	16	0.063	5.584	0.034	0.016	-99	0.20
5 3/4 - 16 16-UN	5.7500	16	0.063	5.709	0.034	0.016	-99	0.20
5 7/8 - 16 16-UN	5.8750	16	0.063	5.834	0.034	0.016	-99	0.20
6 - 16 16-UN	6.0000	16	0.063	5.959	0.034	0.016	-99	0.19
9/16 - 12 12-UN	0.5620	12	0.083	0.508	0.045	0.021	0.486	2.99
5/8 - 12 12-UN	0.6250	12	0.083	0.571	0.045	0.021	0.549	2.66
11/16 - 12 12-UN	0.6870	12	0.083	0.633	0.045	0.021	0.611	2.40
3/4 - 12 12-UN	0.7500	12	0.083	0.696	0.045	0.021	0.674	2.18
13/16 - 12 12-UN	0.8120	12	0.083	0.758	0.045	0.021	0.736	2.00
7/8 - 12 12-UN	0.8750	12	0.083	0.821	0.045	0.021	0.799	1.85
15/16 - 12 12-UN	0.9370	12	0.083	0.883	0.045	0.021	0.861	1.72
1 - 12 12-UN	1.0000	12	0.083	0.946	0.045	0.021	0.924	1.61
1 1/16 - 12 12-UN	1.0620	12	0.083	1.008	0.045	0.021	-99	1.51
1 1/8 - 12 12-UN	1.1250	12	0.083	1.071	0.045	0.021	-99	1.42
1 3/16 - 12 12-UN	1.1870	12	0.083	1.133	0.045	0.021	-99	1.34
1 1/4 - 12 12-UN	1.2500	12	0.083	1.196	0.045	0.021	-99	1.27
1 5/16 - 12 12-UN	1.3120	12	0.083	1.258	0.045	0.021	-99	1.21
1 3/8 - 12 12-UN	1.3750	12	0.083	1.321	0.045	0.021	-99	1.15
1 7/16 - 12 12-UN	1.4370	12	0.083	1.383	0.045	0.021	-99	1.10
1 1/2 - 12 12-UN	1.5000	12	0.083	1.446	0.045	0.021	-99	1.05
1 9/16 - 12 12-UN	1.5620	12	0.083	1.508	0.045	0.021	-99	1.01
1 5/8 - 12 12-UN	1.6250	12	0.083	1.571	0.045	0.021	-99	0.97
1 11/16 - 12 12-UN	1.6870	12	0.083	1.633	0.045	0.021	-99	0.93
1 3/4 - 12 12-UN	1.7500	12	0.083	1.696	0.045	0.021	-99	0.90
1 13/16 - 12 12-UN	1.8120	12	0.083	1.758	0.045	0.021	-99	0.86
1 7/8 - 12 12-UN	1.8750	12	0.083	1.821	0.045	0.021	-99	0.83
1 15/16 - 12 12-UN	1.9370	12	0.083	1.883	0.045	0.021	-99	0.81
2 - 12 12-UN	2.0000	12	0.083	1.946	0.045	0.021	-99	0.78
2 1/8 - 12 12-UN	2.1250	12	0.083	2.071	0.045	0.021	-99	0.73
2 1/4 - 12 12-UN	2.2500	12	0.083	2.196	0.045	0.021	-99	0.69
2 3/8 - 12 12-UN	2.3750	12	0.083	2.321	0.045	0.021	-99	0.65
2 1/2 - 12 12-UN	2.5000	12	0.083	2.446	0.045	0.021	-99	0.62
2 5/8 - 12 12-UN	2.6250	12	0.083	2.571	0.045	0.021	-99	0.59
2 3/4 - 12 12-UN	2.7500	12	0.083	2.696	0.045	0.021	-99	0.56
2 7/8 - 12 12-UN	2.8750	12	0.083	2.821	0.045	0.021	-99	0.54
3 - 12 12-UN	3.0000	12	0.083	2.946	0.045	0.021	-99	0.52
3 1/8 - 12 12-UN	3.1250	12	0.083	3.071	0.045	0.021	-99	0.49
3 1/4 - 12 12-UN	3.2500	12	0.083	3.196	0.045	0.021	-99	0.48
3 3/8 - 12 12-UN	3.3750	12	0.083	3.321	0.045	0.021	-99	0.46
3 1/2 - 12 12-UN	3.5000	12	0.083	3.446	0.045	0.021	-99	0.44
3 5/8 - 12 12-UN	3.6250	12	0.083	3.571	0.045	0.021	-99	0.43
3 3/4 - 12 12-UN	3.7500	12	0.083	3.696	0.045	0.021	-99	0.41
3 7/8 - 12 12-UN	3.8750	12	0.083	3.821	0.045	0.021	-99	0.40
4 - 12 12-UN	4.0000	12	0.083	3.946	0.045	0.021	-99	0.39
4 1/8 - 12 12-UN	4.1250	12	0.083	4.071	0.045	0.021	-99	0.37
4 1/4 - 12 12-UN	4.2500	12	0.083	4.196	0.045	0.021	-99	0.36
4 3/8 - 12 12-UN	4.3750	12	0.083	4.321	0.045	0.021	-99	0.35
4 1/2 - 12 12-UN	4.5000	12	0.083	4.446	0.045	0.021	-99	0.34
4 5/8 - 12 12-UN	4.6250	12	0.083	4.571	0.045	0.021	-99	0.33
4 3/4 - 12 12-UN	4.7500	12	0.083	4.696	0.045	0.021	-99	0.32
4 7/8 - 12 12-UN	4.8750	12	0.083	4.821	0.045	0.021	-99	0.32
5 - 12 12-UN	5.0000	12	0.083	4.946	0.045	0.021	-99	0.31
5 1/8 - 12 12-UN	5.1250	12	0.083	5.071	0.045	0.021	-99	0.30
5 1/4 - 12 12-UN	5.2500	12	0.083	5.196	0.045	0.021	-99	0.29
5 3/8 - 12 12-UN	5.3750	12	0.083	5.321	0.045	0.021	-99	0.29
5 1/2 - 12 12-UN	5.5000	12	0.083	5.446	0.045	0.021	-99	0.28
5 5/8 - 12 12-UN	5.6250	12	0.083	5.571	0.045	0.021	-99	0.27
5 3/4 - 12 12-UN	5.7500	12	0.083	5.696	0.045	0.021	-99	0.27
5 7/8 - 12 12-UN	5.8750	12	0.083	5.821	0.045	0.021	-99	0.26
6 - 12 12-UN	6.0000	12	0.083	5.946	0.045	0.021	-99	0.26
1 - 8 8-UN	1.0000	8	0.125	0.919	0.068	0.031	0.886	2.48
1 1/16 - 8 8-UN	1.0620	8	0.125	0.981	0.068	0.031	-99	2.32
1 1/8 - 8 8-UN	1.1250	8	0.125	1.044	0.068	0.031	-99	2.18
1 3/16 - 8 8-UN	1.1870	8	0.125	1.106	0.068	0.031	-99	2.06
1 1/4 - 8 8-UN	1.2500	8	0.125	1.169	0.068	0.031	-99	1.95
1 5/16 - 8 8-UN	1.3120	8	0.125	1.231	0.068	0.031	-99	1.85
1 3/8 - 8 8-UN	1.3750	8	0.125	1.294	0.068	0.031	-99	1.76
1 7/16 - 8 8-UN	1.4370	8	0.125	1.356	0.068	0.031	-99	1.68
1 1/2 - 8 8-UN	1.5000	8	0.125	1.419	0.068	0.031	-99	1.61
1 9/16 - 8 8-UN	1.5620	8	0.125	1.481	0.068	0.031	-99	1.54
1 5/8 - 8 8-UN	1.6250	8	0.125	1.544	0.068	0.031	-99	1.48
1 11/16 - 8 8-UN	1.6870	8	0.125	1.606	0.068	0.031	-99	1.42
1 3/4 - 8 8-UN	1.7500	8	0.125	1.669	0.068	0.031	-99	1.37
1 13/16 - 8 8-UN	1.8120	8	0.125	1.731	0.068	0.031	-99	1.32
1 7/8 - 8 8-UN	1.8750	8	0.125	1.794	0.068	0.031	-99	1.27
1 15/16 - 8 8-UN	1.9370	8	0.125	1.856	0.068	0.031	-99	1.23
2 - 8 8-UN	2.0000	8	0.125	1.919	0.068	0.031	-99	1.19
2 1/8 - 8 8-UN	2.1250	8	0.125	2.044	0.068	0.031	-99	1.12
2 1/4 - 8 8-UN	2.2500	8	0.125	2.169	0.068	0.031	-99	1.05
2 3/8 - 8 8-UN	2.3750	8	0.125	2.294	0.068	0.031	-99	0.99
2 1/2 - 8 8-UN	2.5000	8	0.125	2.419	0.068	0.031	-99	0.94
2 5/8 - 8 8-UN	2.6250	8	0.125	2.544	0.068	0.031	-99	0.90
2 3/4 - 8 8-UN	2.7500	8	0.125	2.669	0.068	0.031	-99	0.85
2 7/8 - 8 8-UN	2.8750	8	0.125	2.794	0.068	0.031	-99	0.82
3 - 8 8-UN	3.0000	8	0.125	2.919	0.068	0.031	-99	0.78
3 1/8 - 8 8-UN	3.1250	8	0.125	3.044	0.068	0.031	-99	0.75
3 1/4 - 8 8-UN	3.2500	8	0.125	3.169	0.068	0.031	-99	0.72
3 3/8 - 8 8-UN	3.3750	8	0.125	3.294	0.068	0.031	-99	0.69
3 1/2 - 8 8-UN	3.5000	8	0.125	3.419	0.068	0.031	-99	0.67
3 5/8 - 8 8-UN	3.6250	8	0.125	3.544	0.068	0.031	-99	0.64
3 3/4 - 8 8-UN	3.7500	8	0.125	3.669	0.068	0.031	-99	0.62
3 7/8 - 8 8-UN	3.8750	8	0.125	3.794	0.068	0.031	-99	0.60
4 - 8 8-UN	4.0000	8	0.125	3.919	0.068	0.031	-99	0.58
4 1/8 - 8 8-UN	4.1250	8	0.125	4.044	0.068	0.031	-99	0.56
4 1/4 - 8 8-UN	4.2500	8	0.125	4.169	0.068	0.031	-99	0.55
4 3/8 - 8 8-UN	4.3750	8	0.125	4.294	0.068	0.031	-99	0.53
4 1/2 - 8 8-UN	4.5000	8	0.125	4.419	0.068	0.031	-99	0.52
4 5/8 - 8 8-UN	4.6250	8	0.125	4.544	0.068	0.031	-99	0.50
4 3/4 - 8 8-UN	4.7500	8	0.125	4.669	0.068	0.031	-99	0.49
4 7/8 - 8 8-UN	4.8750	8	0.125	4.794	0.068	0.031	-99	0.48
5 - 8 8-UN	5.0000	8	0.125	4.919	0.068	0.031	-99	0.46
5 1/8 - 8 8-UN	5.1250	8	0.125	5.044	0.068	0.031	-99	0.45
5 1/4 - 8 8-UN	5.2500	8	0.125	5.169	0.068	0.031	-99	0.44
5 3/8 - 8 8-UN	5.3750	8	0.125	5.294	0.068	0.031	-99	0.43
5 1/2 - 8 8-UN	5.5000	8	0.125	5.419	0.068	0.031	-99	0.42
5 5/8 - 8 8-UN	5.6250	8	0.125	5.544	0.068	0.031	-99	0.41
5 3/4 - 8 8-UN	5.7500	8	0.125	5.669	0.068	0.031	-99	0.40
5 7/8 - 8 8-UN	5.8750	8	0.125	5.794	0.068	0.031	-99	0.39
6 - 8 8-UN	6.0000	8	0.125	5.919	0.068	0.031	-99	0.39
1 3/8 - 6 6-UN	1.3750	6	0.167	1.267	0.090	0.042	-99	2.40
1 7/16 - 6 6-UN	1.4370	6	0.167	1.329	0.090	0.042	-99	2.29
1 1/2 - 6 6-UN	1.5000	6	0.167	1.392	0.090	0.042	-99	2.18
1 9/16 - 6 6-UN	1.5620	6	0.167	1.454	0.090	0.042	-99	2.09
1 5/8 - 6 6-UN	1.6250	6	0.167	1.517	0.090	0.042	-99	2.00
1 11/16 - 6 6-UN	1.6870	6	0.167	1.579	0.090	0.042	-99	1.92
1 3/4 - 6 6-UN	1.7500	6	0.167	1.642	0.090	0.042	-99	1.85
1 13/16 - 6 6-UN	1.8120	6	0.167	1.704	0.090	0.042	-99	1.78
1 7/8 - 6 6-UN	1.8750	6	0.167	1.767	0.090	0.042	-99	1.72
1 15/16 - 6 6-UN	1.9370	6	0.167	1.829	0.090	0.042	-99	1.66
2 - 6 6-UN	2.0000	6	0.167	1.892	0.090	0.042	-99	1.61
2 1/8 - 6 6-UN	2.1250	6	0.167	2.017	0.090	0.042	-99	1.51
2 1/4 - 6 6-UN	2.2500	6	0.167	2.142	0.090	0.042	-99	1.42
2 3/8 - 6 6-UN	2.3750	6	0.167	2.267	0.090	0.042	-99	1.34
2 1/2 - 6 6-UN	2.5000	6	0.167	2.392	0.090	0.042	-99	1.27
2 5/8 - 6 6-UN	2.6250	6	0.167	2.517	0.090	0.042	-99	1.21
2 3/4 - 6 6-UN	2.7500	6	0.167	2.642	0.090	0.042	-99	1.15
2 7/8 - 6 6-UN	2.8750	6	0.167	2.767	0.090	0.042	-99	1.10
3 - 6 6-UN	3.0000	6	0.167	2.892	0.090	0.042	-99	1.05
3 1/8 - 6 6-UN	3.1250	6	0.167	3.017	0.090	0.042	-99	1.01
3 1/4 - 6 6-UN	3.2500	6	0.167	3.142	0.090	0.042	-99	0.97
3 3/8 - 6 6-UN	3.3750	6	0.167	3.267	0.090	0.042	-99	0.93
3 1/2 - 6 6-UN	3.5000	6	0.167	3.392	0.090	0.042	-99	0.90
3 5/8 - 6 6-UN	3.6250	6	0.167	3.517	0.090	0.042	-99	0.86
3 3/4 - 6 6-UN	3.7500	6	0.167	3.642	0.090	0.042	-99	0.83
3 7/8 - 6 6-UN	3.8750	6	0.167	3.767	0.090	0.042	-99	0.81
4 - 6 6-UN	4.0000	6	0.167	3.892	0.090	0.042	-99	0.78
4 1/8 - 6 6-UN	4.1250	6	0.167	4.017	0.090	0.042	-99	0.76
4 1/4 - 6 6-UN	4.2500	6	0.167	4.142	0.090	0.042	-99	0.73
4 3/8 - 6 6-UN	4.3750	6	0.167	4.267	0.090	0.042	-99	0.71
4 1/2 - 6 6-UN	4.5000	6	0.167	4.392	0.090	0.042	-99	0.69
4 5/8 - 6 6-UN	4.6250	6	0.167	4.517	0.090	0.042	-99	0.67
4 3/4 - 6 6-UN	4.7500	6	0.167	4.642	0.090	0.042	-99	0.65
4 7/8 - 6 6-UN	4.8750	6	0.167	4.767	0.090	0.042	-99	0.64
5 - 6 6-UN	5.0000	6	0.167	4.892	0.090	0.042	-99	0.62
5 1/8 - 6 6-UN	5.1250	6	0.167	5.017	0.090	0.042	-99	0.61
5 1/4 - 6 6-UN	5.2500	6	0.167	5.142	0.090	0.042	-99	0.59
5 3/8 - 6 6-UN	5.3750	6	0.167	5.267	0.090	0.042	-99	0.58
5 1/2 - 6 6-UN	5.5000	6	0.167	5.392	0.090	0.042	-99	0.56
5 5/8 - 6 6-UN	5.6250	6	0.167	5.517	0.090	0.042	-99	0.55
5 3/4 - 6 6-UN	5.7500	6	0.167	5.642	0.090	0.042	-99	0.54
5 7/8 - 6 6-UN	5.8750	6	0.167	5.767	0.090	0.042	-99	0.53
6 - 6 6-UN	6.0000	6	0.167	5.892	0.090	0.042	-99	0.52
2 1/2 - 4 4-UN	2.5000	4	0.250	2.338	0.135	0.063	-99	1.95
2 5/8 - 4 4-UN	2.6250	4	0.250	2.463	0.135	0.063	-99	1.85
2 3/4 - 4 4-UN	2.7500	4	0.250	2.588	0.135	0.063	-99	1.76
2 7/8 - 4 4-UN	2.8750	4	0.250	2.713	0.135	0.063	-99	1.68
3 - 4 4-UN	3.0000	4	0.250	2.838	0.135	0.063	-99	1.61
3 1/8 - 4 4-UN	3.1250	4	0.250	2.963	0.135	0.063	-99	1.54
3 1/4 - 4 4-UN	3.2500	4	0.250	3.088	0.135	0.063	-99	1.48
3 3/8 - 4 4-UN	3.3750	4	0.250	3.213	0.135	0.063	-99	1.42
3 1/2 - 4 4-UN	3.5000	4	0.250	3.338	0.135	0.063	-99	1.37
3 5/8 - 4 4-UN	3.6250	4	0.250	3.463	0.135	0.063	-99	1.32
3 3/4 - 4 4-UN	3.7500	4	0.250	3.588	0.135	0.063	-99	1.27
3 7/8 - 4 4-UN	3.8750	4	0.250	3.713	0.135	0.063	-99	1.23
4 - 4 4-UN	4.0000	4	0.250	3.838	0.135	0.063	-99	1.19
4 1/8 - 4 4-UN	4.1250	4	0.250	3.963	0.135	0.063	-99	1.15
4 1/4 - 4 4-UN	4.2500	4	0.250	4.088	0.135	0.063	-99	1.12
4 3/8 - 4 4-UN	4.3750	4	0.250	4.213	0.135	0.063	-99	1.08
4 1/2 - 4 4-UN	4.5000	4	0.250	4.338	0.135	0.063	-99	1.05
4 5/8 - 4 4-UN	4.6250	4	0.250	4.463	0.135	0.063	-99	1.02
4 3/4 - 4 4-UN	4.7500	4	0.250	4.588	0.135	0.063	-99	0.99
4 7/8 - 4 4-UN	4.8750	4	0.250	4.713	0.135	0.063	-99	0.97
5 - 4 4-UN	5.0000	4	0.250	4.838	0.135	0.063	-99	0.94
5 1/8 - 4 4-UN	5.1250	4	0.250	4.963	0.135	0.063	-99	0.92
5 1/4 - 4 4-UN	5.2500	4	0.250	5.088	0.135	0.063	-99	0.90
5 3/8 - 4 4-UN	5.3750	4	0.250	5.213	0.135	0.063	-99	0.87
5 1/2 - 4 4-UN	5.5000	4	0.250	5.338	0.135	0.063	-99	0.85
5 5/8 - 4 4-UN	5.6250	4	0.250	5.463	0.135	0.063	-99	0.83
5 3/4 - 4 4-UN	5.7500	4	0.250	5.588	0.135	0.063	-99	0.82
5 7/8 - 4 4-UN	5.8750	4	0.250	5.713	0.135	0.063	-99	0.80
6 - 4 4-UN	6.0000	4	0.250	5.838	0.135	0.063	-99	0.78

limits of Thread Dimensions (UNC, UNF & UNEF)

To manufacture or measure a thread, one has to know the maximum and minimum permissible values of the basic dimensions. These values are calculated according to the thread class (See below). To understand classes, you first need to understand the terms Allowance (Sometimes referred to as deviation) and Tolerances.

Definition of terms:

Allowance (Deviation): The minimum permissible distance between the basic and actual profile.
Tolerance: The width of the tolerance field of a diameter on the actual thread profile. (Pitch, Major & Minor diameters)

A small allowance means that the assembly of a male and female thread will be harder, but after assembly, there will be less freedom of movement.
A large allowance means that the assembly of a male and female thread will be easier, but after assembly, there will be more freedom of movement.
The allowance size does not influence a thread’s production difficulty or price.
A wide tolerance is easier and cheaper to produce but yields a larger spread between threads.
A narrow tolerance is challenging to produce and more expensive but yields a smaller spread between threads.

Unified Thread Classes

The class is defined by a two-character code.
- The first character defines is a digit between 1 and 3. 1=Loose fit, 2=Medium fit, and 3=Tight fit.
- The second character is a letter. A=External thread and B=Internal thread.

In the Unified Inch thread system, only classes 1A & 2A have an allowance. The allowance for the two classes is the same.
The other 4 classes have an allowance of Zero.
All the internal thread profiles (B classes) have no allowance.

Classes 1A & 1B: These classes are suitable for applications where a liberal tolerance and allowance are required to permit easy assembly. The maximum diameters of Class 1A threads are smaller than the basic diameter by the allowance amount. The minimum diameters of Class 1B threads are equal to the basic diameters and consequently afford no allowance at maximum material condition.
Classes 2A & 2B: Classes 2A (external) and 2B (internal) are the default classes used for commercial production of Nut, Bols, and otehr threaded fasteners. They are the default class unless otherwise specified. they have the same allowance as classes 1A/1B. However, they have a narrower tolerance field. The difficulty of assembly is the same, but the spread between different parts in a production batch is smaller.
Classes 3A & 3B: These classes are suitable for applications where tight fit and accuracy of thread elements are essential. The maximum diameters of Class 3A threads and the minimum diameters of Class 3B threads are the same (Both have zero allowance). The accuracy is high, but the assembly is difficult.
Combinations of Classes: The engineer can select any valid class for the male and female threads to achieve his design goals. The valid classes are defined in ASTM B1.1 as follows:
- Classes 2A, 2A, 3B, and 3B are always valid.
- Classes 1A & 1B are valid only for UNC threads with a nominal diameter equal to or larger than 1/4″.

Unified Thread Allowance.

The allowance es should be calculated for external threads with classes 1A and 2A. The allowance of both classes is the same and equals 0.3 times the pitch diameter tolerance of class 2A. It is the function of 3 parameters.

D – Basic (nominal diameter)
P – Pitch (1/TPI)
LE – Length of engagement. If not explicitly specified, the length of engagement is assumed to be 5 pitches. (LE=5*P)
All parameters are in inches

\( \large es = 0.3 \times \left [ 0.0015 \times \sqrt[3]{D} + 0.0015 \times \sqrt{LE} + 0.0015 \times \sqrt[3]{P^{2}} \right ] \)

\begin{array} \large \,es& = 0.3 \times\,[\,0.0015 \times \sqrt[3]{D} &\\ & +\,0.0015 \times \sqrt{LE}&\\ & + 0.0015 \times \sqrt[3]{P^{2}}\,] \end{array}

The result should be rounded to 6 decimal places.
ASTM B1.1 lists in a long chart the allowance for each thread size. However, the results of this formula are 100% accurate, and there is no need to browse the chart.
You can use our Advanced Threading Calculator to obtain the allowance according to a thread description or use the mini-calculator below.

Unified Thread Allowance Calculator

Unified Thread Tolerances

The tolerances T_D for internal threads and T_d for external threads are derived from the class. The tolerances can be calculated according to the below formulas.

T_d – Tolerance for External Major Diameter
T_d2 – Tolerance for External Pitch Diameter
T_D1 – Tolerance for Internal Minor Diameter
T_D2 – Tolerance for Internal Pitch Diameter
T – Base Tolerance (The tolerance of CLASS 2A pitch diameter is the base tolerance from which other tolerances are derived)
D – Basic thread diameter.
P – Pitch (1/TPI).
LE – Length of engagement. (If unknown, the default is 5 * P)
All input parameters and results are in Inches.

Base Tolerance Formula

\( \large T = 0.0015 \times \sqrt[3]{D} + 0.0015 \times \sqrt{LE} + 0.0015 \times \sqrt[3]{P^{2}}\)

\begin{array} \large \,T& = \,0.0015 \times \sqrt[3]{D} &\\ & +\,0.0015 \times \sqrt{LE}&\\ & + 0.0015 \times \sqrt[3]{P^{2}} \end{array}

Formulas for External thread
(Classes 1A,2A & 3A)

\( \large T_{d(1A)} = 0.3 \times T \)

\( \large T_{d2(1A)} = 1.5 \times T \)

\( \large T_{d(2A)} = 0.06 \times \sqrt[3]{P} \)

\( \large T_{d2(2A)} = T \)

\( \large T_{d(3A)} = 0.06 \times \sqrt[3]{P} \)

\( \large T_{d2(3A)} = 0.75 \times T \)

Formulas for Internal Thread
(Classes 1B,2B & 3B)

\( \large T_{d1(1B)} = 0.25 \times P\,-\,0.4 \times P^{2} \)

\( \large T_{d2(1B)} = 1.95 \times T \)

\( \large T_{d1(2B)} = 0.25 \times P\,-\,0.4 \times P^{2} \)

\( \large T_{d2(2B)} = 1.30 \times T \)

\(\begin{array}{ll} \large T_{d1(3B)}=&0.05 \times \sqrt[3]{P} + &\\ &0.003 \times \frac{P}{D}\,-\,0.002 \end{array} \)

\( \large T_{d2(3B)} = 0.975 \times T \)

The above formulas can be used in most cases. However, ASTM B1.1 lists various scenarios where other formulas or quirky rounding rules apply. Use our Advanced Threading Calculator to get exact results for any thread.

Usage notes for the above formulas:

The result should be rounded to 6 decimal places.
Formulas for external threads are valid for all threads.
Formulas for internal threads are valid only for thread diameters above 1/4″, a pitch between 4 and 80 TPI, and engagement lengths up to 1.5 X D.
In some cases, ASTM B1.1 dictates special rounding rules.
You can use the Threading Calculator, which automatically considers all the above rules.

Unified Thread limits Calculations

Once the T_d, T_D, & es values are known, the final limits can be calculated according to the below formulas.

Formulas for Limits of a Metric External Thread

Unified Inch Thread external tolerances sketch

\( \large d_{max}=d-{es} \)
\( \large d_{min}=d_{max}-T_d \)
\( \large d_{2max} = d2 – es \)
\( \large d_{2min}=d_{2max}-T_{d2} \)

Formulas for Limits of a Metric InternalThread

Unified Inch Thread internal tolerances sketch

\( \large D_{1min}=D \)
\( \large D_{1max}=D_{1min}+T_{D1} \)
\( \large D_{2minx} = D_2 \)
\( \large D_{2max}=D_{2min}+ T_{D2} \)

Related Glossary Terms:

SpeeDoctor

ThreaDoctor

Each Data-Sheet Includes:

Convert material standards:

SpeeDoctor

ThreaDoctor

Each Data-Sheet Includes:

Convert material standards:

Unified Screw Threads (UNC/UNF/UNEF): Charts & Formulas

List of Charts

Overview