logo

  logo9  MARYLAND METRICS
Technical Data Chart

THINK!- MARYLAND METRICS - The One-Stop Source For Metric And British Sized Fasteners, Wrenches, Cutting, & Measuring Tools, Metal Shapes, Oil Seals, O-Rings, Mechanical Power Transmission Equipment, Bearings, Hydraulic And Pneumatic Fittings & Tubing, Workholding Components, Plumbing Fittings, & Some Electrical & Electronic Components. Click to go to Maryland Metrics home page
MARYLAND METRICS THREAD IDENTIFICATION CHART
For diagrams not on this page see the Thread Identification Chart: Page Index

TO IDENTIFY AN UNKNOWN THREAD, CERTAIN TOOLS AND DATA ARE NECESSARY. INCLUDED IN THESE CHARTS ARE A HELPFUL COMPILATION OF THE DATA NEEDED FOR THE IDENTIFICATION OF MOST EXTERNAL (MALE) THREADS FROM THE THREE MOST POPULAR THREAD SYSTEMS IN THE WORLD, METRIC STANDARDS, U.S.A.(INCH) STANDARDS, AND THE BRITISH (INCH) STANDARDS. ALSO THIS CHART WILL OUTLINE THE USEFUL TOOLS AND PROCEDURES IN ATTEMPTING TO IDENTIFY AN UNKNOWN THREAD.

THESE ARE THE THREE BASIC STEPS TO IDENTIFY A THREAD:

1. MEASURE THE MAJOR DIAMETER OF THE MALE THREAD. {THE MAJOR DIAMETER IS THE OUTSIDE DIAMETER (OD) OF THE MALE THREAD}. IF YOU ARE TRYING TO IDENTIFY AN INTERNAL (FEMALE) THREAD THESE DATA CHARTS WILL NOT CONTAIN SUFFICIENT INFORMATION. FOR ADDITIONAL INFORMATION ON MEASURING INTERNAL (FEMALE) THREADS; SEE THE INSTRUCTIONS IN CHART VIII.

2. DETERMINE THE NUMBER OF THREADS PER INCH {OR THE NUMBER OF THREADS PER CENTIMETER (cm)}. SEE SECTION (B) FOR CONVERSIONS FROM PITCH TO THREADS PER INCH, AND/OR THREADS PER CENTIMETER. AN IDEAL WAY TO ACCOMPLISH THIS MEASUREMENT IS WITH PITCH GAGES OR WITH THREAD GAGES (Note: PITCH GAGES ARE QUITE INEXPENSIVE). HOWEVER, USING A RULE AND TAKING A CAREFUL COUNT OF THREADS IS NORMALLY ACCEPTABLE.

3. COMPARE YOUR MEASUREMENTS WITH THE DATA CHARTS IN SECTION (A).

CHART I




CHART II

NOTE: CLASS OF FIT - SUCH AS THE U.S.A. '2A/2B' OR THE METRIC '6G/6h' ARE BEYOND THE SCOPE OF THE DATA INCLUDED IN THESE CHARTS.

SOME HELPFUL NOTES ABOUT THREADS;

1. THE METRIC THREAD DESIGNATION USES PITCH IN PLACE OF THE MORE FAMILIAR U.S.A. METHOD OF THREADS PER INCH. PITCH IS THE DISTANCE IN mm FROM ANY ONE POINT ON A THREAD TO A CORRESPONDING POINT ON THE NEXT THREAD, WHEN MEASURED PARALLEL TO ITS AXIS.

2. METRIC COARSE THREAD DOES NOT HAVE TO HAVE PITCH SPECIFIED. THE ABSENCE OF THE PITCH SPECIFICATION INDICATES THAT THE THREAD WILL BE FROM THE COARSE THREAD SERIES.

3. THE NOMINAL DIAMETER OF METRIC PIPE THREADS, BOTH TAPERED AND PARALLEL IS THE SAME AS THE MAJOR DIAMETER (OD) OF THE THREAD. HOWEVER, THE U.S.A., BRITISH AND JAPANESE NOMINAL PIPE THREAD DIAMETERS CORRESPOND TO THE APPROXIMATE INSIDE DIAMETER (ID) OF THE PIPE OR TUBE. IN SECTION (A), ALL THE THREADS ARE LISTED IN ASCENDING MAJOR DIAMETER SIZE ORDER. THIS PLACES THE U.S.A., BRITISH AND JAPANESE PIPE THREADS AMONG THREAD DIAMETERS WHICH ARE LARGER THAN THEIR NOMINAL SIZE.

4. MOST METRIC COUNTRIES IN EUROPE AND ASIA USE THE BRITISH BASED INCH SYSTEM (ISO) FOR MEASURING NON-HYDRAULIC/PNEUMATIC PIPE AND TUBING THREADS. SOME EXAMPLES OF THESE THREAD DESIGNATIONS FOLLOW:

THREADS EQUIVALENT TO BSPP/BSPF (BRITISH STANDARD PIPE - PARALLEL) ARE DESIGNATED IN GERMANY AS: G 1/4; IN FRANCE: G 1/4 cyl; IN JAPAN: PF 1/4; IN BRITAIN: R 1/4 Tr.

THREADS EQUIVALENT TO BSPT (BRITISH STANDARD PIPE - TAPERED) ARE DESIGNATED IN GERMANY AS: R 1/4 keg; IN FRANCE: G 1/4 co; IN JAPAN: PT 1/4; IN BRITAIN: R 1/4.

THE REFERENCE STANDARDS FOR ISO R228 PARALLEL PIPE THREAD ARE DESIGNATED AS: GERMANY - DIN 259; BRITAIN - BS 2779; JAPAN - JIS B 0202

THE REFERENCE STANDARDS FOR ISO R7 TAPERED PIPE THREAD ARE DESIGNATED AS: GERMANY - DIN 2999; BRITAIN - BS 21; JAPAN - JIS B 0203

5. IN THE BRITISH SYSTEM THERE IS NO NEED TO INDICATE THE NUMBER OF THREADS PER INCH. EACH OF THE BRITISH THREAD SERIES HAVE ONLY ONE NUMBER OF THREADS PER INCH ALLOCATED WITHIN ITS SERIES AND NOMINAL DIAMETER.

6. THE U.S.A. MINIATURE THREAD SERIES (UNM) IS INTERCHANGEABLE WITH THE CORRESPONDING SIZES OF ISO METRIC THREADS WHERE THE NOMINAL DIAMETERS ARE EQUAL.

7. A FEW ADDITIONAL HINTS TO THREAD SYSTEM IDENTIFICATION ARE AS FOLLOWS: GENERALLY, BOLT HEADS WITH NUMERICAL MARKINGS SUCH AS 8.8, 9.8, 10.9, 12.9, WILL PROBABLY BE METRIC; AND BOLT HEADS WITH LINE/SLASH MARKINGS WILL PROBABLY BE FROM THE U.S.A. GRADE MARKING SYSTEM.



MEASUREMENT PROCEDURES:

1. BY USING A MICROMETER OR CALIPER; DETERMINE THE MAJOR DIAMETER (ACTUAL OUTSIDE DIAMETER) OF THE MALE SCREW THREAD. IT MAY BE MEASURED IN DECIMAL INCHES OR MILLIMETERS. NOTE THAT THE MAJOR DIAMETER IS OFTEN SLIGHTLY UNDERSIZED FOR CLEARANCE, BUT IS NORMALLY NEVER OVERSIZED. (SEE DIAGRAM III).

2. BY USING A RULE OR CALIPER, DETERMINE THE NUMBER OF THREADS PER INCH. (SEE DIAGRAM III). OR IF AVAILABLE, A MORE ACCURATE METHOD IS TO USE A PITCH GAGE OR A THREAD GAGE.

3. GO TO SECTION (A). CHECK THE BASIC MAJOR DIAMETER COLUMNS; LOCATE THE CLOSEST MEASUREMENT IN EITHER THE APPROPRIATE MILLIMETER (mm) OR DECIMAL INCH COLUMN FOR THE NOMINAL DIAMETER THAT YOU HAVE MEASURED IN STEP ONE. MOVE ACROSS THE ROW UNTIL YOU HAVE FOUND A MATCH FOR THE THREADS PER INCH OR PITCH MEASUREMENT FROM STEP TWO.

4. IF THERE IS ONLY ONE THREAD IN THIS ROW, THE THREAD IS NOW IDENTIFIED. HOWEVER IF THERE IS MORE THAN ONE THREAD IN THIS ROW, YOU WILL HAVE TO DETERMINE THE ANGLE OF THE THREAD FOR A FINAL IDENTIFICATION (SEE DIAGRAMS IV THROUGH VII FOR THREAD ANGLES). FOR EXAMPLE, A METRIC SCREW PITCH GAGE WILL READILY SHOW THE DIFFERENCE IN THREAD ANGLES BETWEEN 'BA' (47 1/2 DEGREE) THREADS AND METRIC (60 DEGREE) THREADS.

(CHART IV): TAP DRILL FORMULA FOR METRIC THREADS; NOMINAL OD OF THREAD (MAJOR DIAMETER) - PITCH = TAP DRILL SIZE. (Note: This formula will yield approximately 68% - 77% of thread.) Example: TO FIND THE TAP DRILL SIZE FOR AN M10 x 1.5 THREAD. 10 (OD) - 1.5 (PITCH) = 8.5 mm (TAP DRILL SIZE).

(CHART VIII): HOW TO CALCULATE THE APPROXIMATE NOMINAL MAJOR DIAMETER (OD) OF THE METRIC MALE (EXTERNAL) THREAD WHEN ONLY THE FEMALE (INTERNAL) METRIC THREAD IS AVAILABLE FOR MEASUREMENT.
1. MEASURE VERY CAREFULLY THE PITCH (P) USING A THREAD PITCH GAGE, OR ANY OTHER TYPE OF MEASURING TOOL WHICH WILL GIVE AN ACCURATE READING FOR PITCH.
2. MULTIPLY THE FACTOR VALUE: (F)=1.0825 BY THE PITCH (P) WHICH YIELDS RESULT (R). F x P = R. Example: 1.0825 (F) X 1.75 (P) = 1.8944 (R)
3. MEASURE VERY CAREFULLY THE (ID) INSIDE DIAMETER (MINOR DIAMETER) OF THE FEMALE METRIC THREAD USING AN INTERNAL MICROMETER, INTERNAL CALIPER, OR GAGE PIN.
4. ADD THE MEASURED VALUE FOR THE INSIDE DIAMETER (ID) TO THE RESULT (R) WHICH WILL YIELD THE NOMINAL MAJOR DIAMETER (OD) OF THE FEMALE THREAD. ID + R = OD. Example: ASSUME MEASURED VALUE 10.1036 (ID) + 1.8944 (R) = 12 (OD OR APPROXIMATE NOMINAL MAJOR DIAMETER).


For diagrams not on this page see the Thread Identification Chart: Page Index


SECTION (B)
PITCH CONVERSION TABLE
APPROXIMATE
THREADS per INCH
PITCH mm APPROXIMATE
THREADS per cm
338 1/2 0.075 133.33
317 1/2 0.08 125.00
282 1/4 0.09 111.11
254 0.1 100.00
203 1/4 0.125 80.00
169 1/4 0.15 66.67
145 1/4 0.175 57.14
127 0.2 50.00
101 1/2 0.25 40.00
84 3/4 0.3 33.33
72 1/2 0.35 28.57
63 1/2 0.4 25.00
56 1/2 0.45 22.22
50 3/4 0.5 20.00
42 1/4 0.6 16.67
36 1/4 0.7 14.29
33 3/4 0.75 13.33
31 3/4 0.8 12.50
28 1/4 0.9 11.11
25 1/2 1 10.00
20 1/4 1.25 8.00
17 1.5 6.67
14 1/2 1.75 5.71
12 3/4 2 5.00
10 1/4 2.5 4.00
8 1/2 3 3.33
7 1/4 3.5 2.86
6 1/4 4 2.50
5 3/4 4.5 2.22
5 5 2.00
4 1/2 5.5 1.82
4 1/4 6 1.67

NOTES: [ P=PITCH ] [ 1cm=10mm ] [10/P=Threads/cm ] [25.4/P=Threads/inch ]



CHART III -- DEFINITIONS OF SECTION (A) COLUMN HEADINGS

METRIC AMERICAN BRITISH
M - COARSE AND FINE UNC - UNIFIED NATIONAL COARSE BA - BRITISH ASSOCIATION
MF - FINE; alternative prefix UNF - UNIFIED NATIONAL FINE BSW- BRITISH STANDARD WHITWORTH
M TAPER-METRIC PIPE TAPERED UNEF- UNIFIED NATIONAL EXTRA FINE BSF- BRITISH STANDARD FINE
STANDARD REFERENCES UNM - UNIFIED MINIATURE BSPF-BRITISH STANDARD PIPE - PARALLEL
I - ISO STD. FIRST CHOICE NPT - NATIONAL PIPE TAPERED BSPP-BRITISH STANDARD PIPE - PARALLEL
II -ISO STD. SECOND CHOICE NPS - NATIONAL PIPE STRAIGHT BSPT-BRITISH STANDARD PIPE - TAPERED
III-ISO STD. THIRD CHOICE . PF-JAPANESE CALLOUT FOR BSPF/BSPP
D - DIN, GERMAN STANDARD 8UN - 8 PITCH (all sizes= 8 T.P.I.) PT-JAPANESE CALLOUT FOR BSPT

MARYLAND METRICS -- THREAD IDENTIFICATION CHART: SECTION (A)
(Also see the IMPORTANT notes at the bottom of this table.)

BASIC MAJOR DIAMETER NOMINAL DIAMETER: METRIC STD. REF. METRIC -- PITCH in mm NOMINAL DIAMETER: AMERICAN AMERICAN -- PITCH in THREADS per Inch UNIFIED MINI-ATURE BRITISH ASSOC-IATION NOMINAL DIAM-ETER BRITISH -- PITCH in THREADS per Inch
Inch mm mm . COARSE FINE . UNC UNF UNEF UNM BA No. BRITISH BA BSW BSF BSPT
0.0098 0.25 . . 0.07 . . . . . . 25 . 363 . . .
0.0114 0.29 . . 0.08 . . . . . . 24 . 317 . . .
0.0118 0.30 0.3 D 0.075 . . . . . . . . . . . .
0.0118 0.30 0.3 I 0.08 . 0.30 mm . . 318 0.30 . . . . . .
0.0130 0.33 . . 0.09 . . . . . . 23 . 282 . . .
0.0138 0.35 0.35 II 0.09 . 0.35 mm . . 282 0.35 . . . . . .
0.0146 0.37 . . 0.098 . . . . . . 22 . 254 . . .
0.0157 0.40 0.4 I D 0.1 . 0.40 mm . . 254 0.40 . . . . . .
0.0165 0.42 . . 0.11 . . . . . . 21 . 230.91 . . .
0.0177 0.45 0.45 II 0.1 . 0.45 mm . . 254 0.45 . . . . . .
0.0189 0.48 . . 0.12 . . . . . . 20 . 211.67 . . .
0.0197 0.50 0.5 I D 0.125 . 0.50 mm . . 203 0.50 . . . . . .
0.0209 0.53 . . . . 0 . 160 . . . . . . . .
0.0213 0.54 . . 0.14 . . . . . . 19 . 181.43 . . .
0.0217 0.55 0.55 II 0.125 . 0.55 mm . . 203 0.55 . . . . . .
0.0236 0.60 0.6 I D 0.15 . 0.60 mm . . 169 0.60 . . . . . .
0.0244 0.62 . . 0.15 . . . . . . 18 . 169.33 . . .
0.0276 0.70 0.7 II D 0.175 . 0.70 mm . . 145 0.70 17 . 149.41 . . .
0.0311 0.79 . . 0.19 . . . . . . 16 . 133.68 . . .
0.0315 0.80 0.8 I D 0.2 . 0.80 mm . . 127 0.80 . . . . . .
0.0340 0.86 . . . . 0 . 120 . . . . . . . .
0.0354 0.90 0.9 II D 0.225 . 0.90 mm . . 113 0.90 15 . 120.95 . . .
0.0394 1 1 I D 0.25 0.2 1.00 mm . . 102 1.00 14 . 110.44 . . .
0.0433 1.1 1.1 II 0.25 0.2 1.10 mm . . 102 1.10 . . . . . .
0.0470 1.19 . . . . 0 . 90 . . . . . . . .
0.0472 1.2 1.2 I D 0.25 0.2 1.20 mm . . 102 1.20 13 . 101.6 . . .
0.0512 1.3 . . 0.28 . . . . . . 12 . 90.71 . . .
0.0551 1.4 1.4 II D 0.3 0.2 1.40 mm . . 85 1.40 . . . . . .
0.0591 1.5 1.5 . 0.31 . . . . . . 11 . 81.93 . . .
0.0600 1.524 . . . . #0 . 80 . . . . . . . .
0.0625 1.59 . . . . . . . . . . 1/16 . 60 . .
0.0629 1.6 1.6 I 0.35 0.2 . . . . . . . . . . .
0.0669 1.7 1.7 D 0.35 0.2,0.25 . . . . . 10 . 72.57 . . .
0.0709 1.8 1.8 II 0.35 0.2,(0.4) . . . . . . . . . . .
0.0730 1.854 . . . . #1 64 72 . . . . . . . .
0.0748 1.9 . . 0.39 . . . . . . 9 . 65.13 . . .
0.0781 1.98 . . . . . . . . . . 5/64 . 56 . .
0.0787 2 2 I D 0.4 0.25,0.3 . . . . . . . . . . .
0.0860 2.184 . . . . #2 56 64 . . . . . . . .
0.0866 2.2 2.2 II 0.45 0.25 . . . . . 8 . 59.07 . . .
0.0906 2.3 2.3 D 0.4 0.25,0.35 . . . . . . . . . . .
0.0937 2.38 . . . . . . . . . . 3/32 . 48 . .
0.0984 2.5 2.5 I 0.45 0.35 . . . . . 7 . 52.92 . . .
0.0990 2.515 . . . . #3 48 56 . . . . . . . .
0.1024 2.6 2.6 D 0.45 0.25,0.35 . . . . . . . . . . .
0.1094 2.78 . . . . . . . . . . 7/64 . 48 . .
0.1102 2.8 . . 0.53 . . . . . . 6 . 47.93 . . .
0.1120 2.845 . . . . #4 40 48 . . . . . . . .
0.1181 3 3 I D 0.5 0.35,(0.6) . . . . . . . . . . .
0.1250 3.175 . . . . #5 40 44 . . . 1/8 . 40 . .
0.1260 3.2 . . 0.59 . . . . . . 5 . 43.05 . . .
0.1380 3.5 3.5 II D 0.6 0.35,0.5 #6 32 40 . . . . . . . .
0.1417 3.6 . . 0.66 . . . . . . 4 . 38.49 . . .
0.1563 3.969 . . . . . . . . . . 5/32 . 32 . .
0.1575 4 4 I D 0.7 0.5,(0.75) . . . . . . . . . . .
0.1614 4.1 . . 0.73 . . . . . . 3 . 34.8 . . .
0.1640 4.166 . . . . #8 32 36 . . . . . . . .
0.1772 4.5 4.5 II 0.75 0.5 . . . . . . . . . . .
0.1850 4.7 . . 0.81 . . . . . . 2 . 31.36 . . .
0.1875 4.762 . . . . . . . . . . 3/16 . 24 32 .
0.1900 4.826 . . . . #10 24 32 . . . . . . . .
0.1969 5 5 I D 0.8 0.5,0.75,(0.9) . . . . . . . . . . .
0.2087 5.3 . . 0.9 . . . . . . 1 . 28.22 . . .
0.2160 5.486 . . . . #12 24 28 32 . . . . . . .
0.2165 5.5 5.5 III 0.9 0.5 . . . . . . . . . . .
0.2188 5.556 . . . . . . . . . . 7/32 . 24 28 .
0.2362 6 6 I D 1 0.5,0.75 . . . . . 0 . 25.4 . . .
0.2480 6.3 6.3 GM 1 . . . . . . . 1/8 . . . 28(H)
0.2500 6.35 . . . . 1/4 20 28 32 . . 1/4 . 20 26 .
0.2756 7 7 III D 1 0.5,0.75 . . . . . . . . . . .
0.2812 7.144 . . . . . . . . . . 9/32 . 20 26 .
0.3041 7.723 . . . . . . . . . . 1/16 . . . 28


MARYLAND METRICS -- THREAD IDENTIFICATION CHART: SECTION (A)
Continuation: (Also see the IMPORTANT notes at the bottom of this table.)

BASIC MAJOR DIAMETER NOMINAL DIAMETER METRIC STD. REF. METRIC -- PITCH in mm NOMINAL DIAMETER AMERICAN AMERICAN -- PITCH in THREADS per Inch SPECIAL USE NOTES* NOMINAL DIAMETER BRITISH BRITISH -- PITCH in THREADS per Inch
Inch mm mm . COARSE FINE M TAPER FRACTIONS UNC UNF UNEF NPT 8UN *See table SD FRACTIONS BSW BSF BSPF BSPT
0.3108 7.894 . . . . . 1/16 . . . 27 . . . . . BSPP .
0.3125 7.94 . . . . . 5/16 18 24 32 . . 24(C-J) 24(SAE-F) 5/16 18 22 . .
0.3150 8.00 8 I D 1.25 0.5,0.75,1 1 . . . . . . . . . . . .
0.3543 9.00 9 III D 1.25 0.75,1 . . . . . . . . . . . . .
0.3750 9.53 . . . . . 3/8 16 24 32 . . 24(SAE C-J) 3/8 16 20 . .
0.3830 9.73 . . . . . . . . . . . . 1/8 . . 28 28
0.3937 10.00 10 I D 1.5 0.75,1,1.25 1 . . . . . . . . . . . .
0.4044 10.271 . . . . . 1/8 . . . 27 . . . . . . .
0.4331 11.00 11 III D 1.5 0.75,1,1.25 . . . . . . . . . . . . .
0.4375 11.11 . . . . . 7/16 14 20 28 . . 24(C) 20(SAE J-F) 7/16 14 18 . .
0.4724 12.00 12 I D 1.75 1,1.25,1.5 1.5 . . . . . . . . . . . .
0.5000 12.70 . . . . . 1/2 13 20 28 . . 24(C) 20(SAE J-F) 1/2 12 16 . .
0.5180 13.16 . . . . . . . . . . . . 1/4 . . 19 19
0.5343 13.571 . . . . . 1/4 . . . 18 . . . . . . .
0.5512 14.00 14 II D 2 1,1.25,1.5 . . . . . . . . . . . . .
0.5625 14.29 . . . . . 9/16 12 18 24 . . 24(C) 18(SAE-J) 9/16 12 16 . .
0.5906 15.00 15 III D . 1,1.5 . . . . . . . . . . . . .
0.6250 15.88 . . . . . 5/8 11 18 24 . . 24(C) 18(SAE-F) 5/8 11 14 . .
0.6299 16.00 16 I D 2 1,1.5 1.5 . . . . . . . . . . . .
0.6560 16.662 . . . . . . . . . . . . 3/8 . . 19 19
0.6693 17.00 17 III D . 1,1.5 . . . . . . . . . . . . .
0.6714 17.054 . . . . . 3/8 . . . 18 . . . . . . .
0.6875 17.46 . . . . . 11/16 . . 24 . . 20(C) 18(SAE-F) 11/16 11 14 . .
0.7087 18.00 18 II D 2.5 1,1.5,2 1.5 . . . . . . . . . . . .
0.7500 19.05 . . . . . 3/4 10 16 20 . . 16(SAE-J-F) 3/4 10 12 . .
0.7874 20.00 20 I D 2.5 1,1.5,2 1.5 . . . . . . . . . . . .
0.8125 20.64 . . . . . 13/16 . . 20 . . 18(C) 13/16 10 12 . .
0.8250 20.955 . . . . . . . . . . . . 1/2 . . 14 14
0.8356 21.222 . . . . . 1/2 . . . 14 . . . . . . .
0.8661 22.00 22 II D 2.5 1,1.5,2 1.5 . . . . . . . . . . . .
0.8750 22.23 . . . . . 7/8 9 14 20 . . 14(SAE-F-J) 7/8 9 11 . .
0.9020 22.911 . . . . . . . . . . . . 5/8 . . 14 14
0.9375 23.81 . . . . . 15/16 . . 20 . . 20(C-J) 16(SAE) 15/16 9 . . .
0.9449 24.00 24 I D 3 1,1.5,2 . . . . . . . . . . . . .
0.9843 25.00 25 III D . 1,1.5,2 . . . . . . . . . . . . .
1.0000 25.40 . . . . . 1 8 12 20 . 8 18(C) 14(NF) 1 8 10 . .
1.0236 26.00 26 III D . 1.5 1.5 . . . . . . . . . . . .
1.0410 26.441 . . . . . . . . . . . . 3/4 . . 14 14
1.0460 26.568 . . . . . 3/4 . . . 14 . . . . . . .
1.0625 26.99 . . . . . 1 1/16 . . 18 . 8 14(F) 12(SAE-J) . . . . .
1.0630 27.00 27 II D 3 1,1.5,2 . . . . . . . . . . . . .
1.1024 28.00 28 III D . 1,1.5,2 . . . . . . . . . . . . .
1.1250 28.58 . . . . . 1 1/8 7 12 18 . 8 18(C) 1 1/8 7 9 . .
1.1811 30.00 30 I D 3.5 1,1.5,2,3 . . . . . . . . . . . . .
1.1875 30.16 . . . . . 1 3/16 . . 18 . 8 12(SAE-J) . . . . .
1.1890 30.20 . . . . . . . . . . . . 7/8 . . 14 14
1.2500 31.75 . . . . . 1 1/4 7 12 18 . 8 12(SAE) 1 1/4 7 9 . .
1.2598 32.00 32 III D . 1.5,2 . . . . . . . . . . . . .
1.2992 33.00 33 II D 3.5 1.5,2,3 . . . . . . . . . . . . .
1.3328 33.228 . . . . . 1 . . . 11 1/2 . . . . . . .
1.3090 33.249 . . . . . . . . . . . . 1 . . 11 11
1.3125 33.34 . . . . . 1 5/16 . . 18 . 8 12(SAE-J) . . . . .
1.3750 34.93 . . . . . 1 3/8 6 12 18 . 8 . 1 3/8 6 8 . .
1.3780 35.00 35 III D . 1.5 . . . . . . . SEE TABLE . . . . .
1.4173 36.00 36 I D 4 1.5,2,3 . . . . . . . SD . . . . .
1.4375 36.51 . . . . . 1 7/16 . . 18 . 8 FOR . . . . .
1.4920 37.897 . . . . . . . . . . . SPECIAL 1 1/8 . . 11 .
1.4961 38.00 38 III D . 1.5 . . . . . . . USE . . . . .
1.5000 38.10 . . . . . 1 1/2 6 12 18 . 8 DEFINITIONS 1 1/2 6 8 . .
1.5354 39.00 39 II D 4 1.5,2,3 . . . . . . . . . . . . .
1.5625 39.69 . . . . . 1 9/16 . . 18 . 8 . . . . . .
1.5748 40.00 40 III D . 1.5,2,3 . . . . . . . . . . . . .
1.6250 41.28 . . . . . 1 5/8 . . 18 . 8 12(SAE-J) 1 5/8 5 8 . .
1.6500 41.91 . . . . . . . . . . . . 1 1/4 . . 11 11
1.6535 41.99 42 I D 4.5 1.5,2,3,4 . . . . . . . . . . . . .
1.6600 42.16 . . . . . 1 1/4 . . . 11 1/2 . . . . . . .
1.6875 42.86 . . . . . 1 11/16 . . 18 . 8 . . . . . .
1.7450 44.32 . . . . . . . . . . . . 1 3/8 . . 11 .
1.7500 44.45 . . 16 . . 1 3/4 5 . 16 . 8 . 1 3/4 5 7 . .
1.7717 45.00 45 II D 4.5 1.5,2,3,4 . . . . . . . . . . . . .
1.8750 47.63 . . . . . 1 7/8 . . . . 8 12(SAE-J) 1 7/8 4 1/2 . . .
1.8820 47.802 . . . . . . . . . . . . 1 1/2 . . 11 11
1.8898 48.00 48 I D 5 1.5,2,3,4 . . . . . . . . . . . . .
1.8919 48.054 . . . . . 1 1/2 . . . 11 1/2 . . . . . . .
1.9685 50.00 50 III D . 1.5,2,3 . . . . . . . . . . . . .
2.0000 50.80 . . . . . 2 4 1/2 . 16 . 8 . 2 4 1/2 7 . .
2.0472 52.00 52 II D 5 1.5,2,3,4 . . . . . . . . . . . . .
2.1654 55.00 55 III D . 1.5,2,3,4 . . . . . . . . . . . . .
2.2047 56.00 56 I D 5.5 1.5,2,3,4 . . . . . . . . . . . . .
2.2500 57.15 . . . . . 2 1/4 4 1/2 . . . 8 . 2 1/4 4 6 . .
2.2835 58.00 58 III D . 1.5,2,3,4 . . . . . . . . . . . . .
2.3470 59.613 . . . . . . . . . . . . 2 . . 11 11
2.3622 60.00 60 II D 5.5 1.5,2,3,4 . . . . . . . . . . . . .
2.3658 60.094 . . . . . 2 . . . 11 1/2 . . . . . . .
2.4409 62.00 62 III D . 1.5,2,3,4 . . . . . . . . . . . . .
2.5000 63.50 . . . . . 2 1/2 4 . . . 8 12(SAE-J) 2 1/2 4 6 . .
2.5197 64.00 64 I D 6 1.5,2,3,4 . . . . . . . . . . . . .
Metric Electrical thread
2.4803 63.00 63 . . 1.5 . . . . . . . E . . . . .
2.9528 75.00 75 . . 1.5 . . . . . . . E . . . . .
3.1496 80.00 80 . . 2 . . . . . . . E . . . . .
3.3465 85.00 85 . . 2 . . . . . . . E . . . . .
3.5433 90.00 90 . . 2 . . . . . . . E . . . . .
3.937 100.00 100 . . 2, 3 . . . . . . . E . . . . .
4.3307 110.00 110 . . 2 . . . . . . . E . . . . .
  1. The British thread system is fractionally based, but all thread vee angles are different than the American fractionally or decimally based threads. Most thread per inch values are different than in the American System.
  2. Taper pipe thread major diameters are measured at the guage point.
  3. (H)= BSPT copper pipe thread.
  4. Dimensions within ( ) in the M FINE column are obsolete French or Japanese threads.
  5. Dimensions within ( ) in the BSW column are obsolete British coarse threads.
  6. The 6.3 mm dimension; marked GM is an obsolete General Motors thread.
TABLE (SD) -- SPECIAL USE THREAD DEFINITIONS
C = Compression fittings
J = JIC 37 degree Flare fittings
F = JIC 45 degree Flare fittings
SAE = SAE straight thread
NF = National Fine thread
E = Electrical thread
WARNING: We are not responsible for any technical errors
or typographical errors in this publication.

Corrections and/or suggestions to improve this data chart are welcome.
[ Please send them to: techinfo@mdmetric.com ]
MARYLAND METRICS
P.O.Box 261   Owings Mills, MD 21117
Phones: (410) 358-3130   (800) 638-1830
Faxes: (410) 358-3142  (800) USA-9-FAX   [800-872-9329]

THINK!- MARYLAND METRICS - The One-Stop Source For Metric And British Sized Fasteners, Wrenches, Cutting, & Measuring Tools, Metal Shapes, Oil Seals, O-Rings, Mechanical Power Transmission Equipment, Bearings, Hydraulic And Pneumatic Fittings & Tubing, Workholding Components, Plumbing Fittings, & Some Electrical & Electronic Components. Click to go to Maryland Metrics home page
Phones: (800) 638-1830 or (410) 358-3130 are available Monday-Friday 8:30 AM to 5:30 PM Eastern time.
Faxes: (800) 872-9329 or (410) 358-3142 & E-mail are available anytime.
Warehouse & showroom hours are Monday-Friday 10 AM to 5:30 PM.
[ To: Maryland Metrics home page ] [ To: Maryland Metrics Product Guide ] [ e-mail to Maryland Metrics ]
Please note that all Trademarks and Tradenames are the property of their respective owners.
copyright 1996, 2002, 2006, 2007, 2011, 2014 maryland metrics -- all rights reserved -- ver gg22aCD tict.htm