Marked A2B Drawing No.N733D Item Code C1F19A2
ASTM A453 Grade 660 Class B twelve point
Screws often refered as 12 point flange bolts offered at TorqBolt are
manufactured in accordance with IFI 115 standard in metric and imperial coarse
and fine thread sizes with UNC, UN, UNF, UNEF, UNJF & ISO threads.
DESCRIPTION: (C1F19A2) Flanged twelve-point, external wrenching
screw.
MATERIAL: Precipitation hardening steel conforming to ASTM A453
Grade 660 Class B, 130 ksi tensile strength.
SCREW THREADS: Class 2A UNC, UNF or 8 UN series.
HARDNESS : BRINELL 248 - 341 HB.
SURFACE TEXTURE: Threads, body under head fillet and bearing
area 63 microinch.
HEAD MARKING: A2B as indicated and registered source ID.
FOR USE IN TEMPERATURE UP TO 1200 °F.
All dimensions are in inches unless otherwise indicated.
| THREAD SIZE | A Flange diameter |
H Head height |
J Width across flats |
C Width across corners |
K Chamfer |
M Flange thickness |
R Fillet |
D Body diameter |
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| max | min | max | min | max | min | min | max | max | min | max | min | max | min | |
| 1/4 (0.250) | 0.375 | 0.365 | 0.250 | 0.244 | 0.253 | 0.249 | 0.284 | 0.008 | 0.088 | 0.068 | 0.015 | 0.010 | 0.2500 | 0.2435 |
| 5/16 (0.312) | 0.469 | 0.457 | 0.312 | 0.306 | 0.316 | 0.311 | 0.356 | 0.008 | 0.119 | 0.099 | 0.015 | 0.010 | 0.3120 | 0.3053 |
| 3/8 (0.375) | 0.562 | 0.550 | 0.375 | 0.368 | 0.378 | 0.370 | 0.422 | 0.008 | 0.166 | 0.146 | 0.020 | 0.015 | 0.3750 | 0.3678 |
| 7/16 (0.438) | 0.656 | 0.642 | 0.438 | 0.430 | 0.440 | 0.432 | 0.493 | 0.010 | 0.197 | 0.177 | 0.030 | 0.020 | 0.4380 | 0.4294 |
| 1/2 (0.500) | 0.750 | 0.735 | 0.500 | 0.492 | 0.503 | 0.495 | 0.565 | 0.010 | 0.228 | 0.208 | 0.030 | 0.020 | 0.5000 | 0.4919 |
| 5/8 (0.625) | 0.938 | 0.921 | 0.625 | 0.616 | 0.628 | 0.620 | 0.707 | 0.010 | 0.275 | 0.255 | 0.030 | 0.020 | 0.6250 | 0.6163 |
| 3/4 (0.750) | 1.125 | 1.107 | 0.750 | 0.740 | 0.753 | 0.745 | 0.850 | 0.010 | 0.338 | 0.318 | 0.040 | 0.030 | 0.7500 | 0.7406 |
| 7/8(0.875) | 1.312 | 1.293 | 0.875 | 0.864 | 0.879 | 0.868 | 0.990 | 0.015 | 0.353 | 0.333 | 0.045 | 0.035 | 0.8750 | 0.8647 |
| 1(1.000) | 1.500 | 1.479 | 1.000 | 0.988 | 1.004 | 0.993 | 1.134 | 0.015 | 0.416 | 0.396 | 0.050 | 0.040 | 1.0000 | 0.9886 |
| 1 1/8(1.125) | 1.684 | 1.665 | 1.125 | 1.111 | 1.129 | 1.117 | 1.276 | 0.015 | 0.448 | 0.428 | 0.055 | 0.045 | 1.125 | 1.109 |
| 1 1/4(1.250) | 1.871 | 1.852 | 1.250 | 1.236 | 1.254 | 1.241 | 1.418 | 0.015 | 0.494 | 0.474 | 0.060 | 0.050 | 1.250 | 1.234 |
| 1 3/8(1.375) | 2.058 | 2.038 | 1.375 | 1.360 | 1.379 | 1.366 | 1.561 | 0.015 | 0.541 | 0.521 | 0.065 | 0.055 | 1.375 | 1.357 |
| 1 1/2(1.500) | 2.245 | 2.224 | 1.500 | 1.485 | 1.505 | 1.491 | 1.705 | 0.015 | 0.604 | 0.584 | 0.070 | 0.060 | 1.500 | 1.482 |
| 1 5/8 (1.625) | 2.430 | 2.408 | 1.625 | 1.611 | 1.630 | 1.615 | 1.848 | 0.015 | 0.651 | 0.631 | 0.070 | 0.060 | 1.625 | 1.605 |
| 1 3/4 (1.750) | 2.620 | 2.597 | 1.750 | 1.734 | 1.755 | 1.740 | 2.009 | 0.015 | 0.760 | 0.740 | 0.080 | 0.070 | 1.750 | 1.730 |
| 2 (2.000) | 2.995 | 2.970 | 2.000 | 1.983 | 2.005 | 1.990 | 2.268 | 0.015 | 0.885 | 0.865 | 0.090 | 0.075 | 2.000 | 1.980 |
| 2 1/4 (2.250) | 3.375 | 3.344 | 2.250 | 2.232 | 2.255 | 2.200 | 2.480 | 0.030 | 1.010 | 0.990 | 0.125 | 0.100 | 2.250 | 2.227 |
| 2 1/2 (2.500) | 3.750 | 3.717 | 2.500 | 2.481 | 2.505 | 2.455 | 2.760 | 0.030 | 1.119 | 1.099 | 0.150 | 0.110 | 2.500 | 2.477 |
| THREAD/INCH | 20 UNC | 28 UNF | 18 UNC | 24 UNF | 16 UNC | 24 UNF | ||
|---|---|---|---|---|---|---|---|---|
| T (1) | Thread length | min | 1 | 1.12 | 1.25 | |||
| L | Length | Tol | PART NO. (For other lengths, last three digits are lengths in 16ths.) | |||||
| Preferred Lengths | 3/8 (0.375) 1/2 (0.500) 5/8 (0.625) |
- 0.03 | 21006 21008 21010 |
20006 20008 20010 |
23006 23008 23010 |
22008 22010 |
25008 25010 |
24008 24010 |
| 3/4 (0.750) 7/8 (0.875) 1 (1.000) |
21012 21014 21016 |
20012 20014 20016 |
23012 23014 23016 |
22012 22014 22016 |
25012 25014 25016 |
24012 24014 24016 |
||
| 1 1/4 (1.250) 1 1/2 (1.500) |
- 0.04 | 21020 21024 |
20020 20024 |
23020 23024 |
22020 22024 |
25020 25024 |
24020 24024 |
|
| 1 3/4 (1.750) | 21028 | 20028 | 23028 | 22028 | 25028 | 24028 | ||
| 2 (2.000) 2 1/4 (2.250) 2 1/2 (2.500) |
21032 21036 21040 |
20032 20036 |
23032 23036 23040 |
22032 22036 22040 |
25032 25036 25040 |
24032 24036 24040 |
||
| 2 3/4 (2.750) 3 (3.000) 3 1/4 (3.250) |
- 0.06 | 21044 21048 |
23044 23048 23052 |
25044 25048 25052 |
24048 | |||
| 3 1/2 (3.500) 4 (4.000) 4 1/2 (4.500) 5 (5.000) |
23056 | 25056 25064 25072 25080 |
||||||
| THREAD/INCH | 14 UNC |
20 UNF |
13 UNC |
20 UNF |
11 UNC |
18 UNF |
10 UNC |
|||
|---|---|---|---|---|---|---|---|---|---|---|
| T (1) | Thread length | min | 1.38 | 1.50 | 1.75 | 2.00 | ||||
| L | Length | Tol | PART NO. (For other lengths, last three digits are lengths in 16ths.) | |||||||
| Preferred Lengths | 1/2 (0.500) 5/8 (0.625) 3/4 (0.750) 7/8 (0.875) |
- 0.03 | 27008 27010 27012 27014 |
29008 29010 29012 29014 |
||||||
| 1 (1.000) 1 1/4 (1.250) 1 1/2 (1.500) 1 3/4 (1.750) |
- 0.06 | 27016 27020 27024 27028 |
26016 26020 26024 |
29016 29020 29024 29028 |
28016 28020 28024 28028 |
33016 33020 33024 33028 |
32016 32020 32024 32028 |
35020 35024 35028 |
34020 34024 34028 |
|
| 2 (2.000) 2 1/4 (2.250) 2 1/2 (2.500) |
27032 27036 27040 |
26032 | 29032 29036 29040 |
28032 28036 28040 |
33032 33036 33040 |
32032 32040 |
35032 35036 35040 |
34032 34040 |
||
| 2 3/4 (2.750) 3 (3.000) 3 1/4 (3.250) 3 1/2 (3.500) |
- 0.08 | 27044 27048 27052 27056 |
29044 29048 29052 29056 |
28048 |
33044 33048 33052 33056 |
35044 35048 35052 35056 |
||||
| 4 (4.000) 4 1/2 (4.500) 5 (5.000) 5 1/2 (5.500) 6 (6.000) |
27064 | 29064 29072 29080 29088 29096 |
33064 33072 33080 33088 |
35064 35072 35080 35088 35096 |
||||||
| THREAD/INCH | 9 UNC |
8 UNC |
7 UNC |
8 UN |
7 UNC |
8 UN |
6 UNC |
8 UN |
6 UNC |
8 UN |
||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| T (1) | Thread length | min | 2.25 | 2.50 | 2.82 | 3.12 | 3.44 | 3.75 | ||||
| L | Length | Tol | PART NO. (For other lengths, last three digits are lengths in 16ths.) | |||||||||
| Preferred Lengths | 2 (2.000) 2 1/4 (2.250) 2 1/2 (2.500) |
- 0.10 | 37032 37036 37040 |
39032 39036 39040 |
42032 42036 42040 |
41032 41036 41040 |
45032 45036 45040 |
44032 44036 44040 |
48032 48036 48040 |
47032 47036 47040 |
51032 51036 51040 |
50032 50036 50040 |
| 2 3/4 (2.750) 3 (3.000) 3 1/4 (3.250) |
- 0.14 | 37044 37048 37052 |
39044 39048 39052 |
42044 42048 42052 |
41044 41048 41052 |
45044 45048 45052 |
44044 44048 44052 |
48044 48048 48052 |
47044 47048 47052 |
51044 51048 51052 |
50044 50048 50052 |
|
| 3 1/2 (3.500) 4 (4.000) 4 1/2 (4.500) |
37056 37064 37072 |
39056 39064 39072 |
42056 42064 42072 |
41056 41064 41072 |
45056 45064 45072 |
44056 44064 44072 |
48056 48064 48072 |
47056 47064 47072 |
51056 51064 51072 |
50056 50064 50072 |
||
| 5 (5.000) 5 1/2 (5.500) 6 (6.000) |
37080 37088 37096 |
39080 39088 39096 |
42080 42088 42096 |
41080 41088 41096 |
45080 45088 45096 |
44080 44088 44096 |
48080 48088 48096 |
47080 47088 47096 |
51080 51088 51096 |
50080 50088 50096 |
||
| Greater than (6.000) | - 0.20 | |||||||||||
| THREAD/INCH | 8 UN | 8 UN | 8 UN | 8 UN | 8 UN | ||
|---|---|---|---|---|---|---|---|
| T (1) | Thread length | min | 4.07 | 4.38 | 5.00 | 5.62 | 6.25 |
| L | Length | Tol | (For other lengths, last three digits are lengths in 16ths.) | ||||
| Preferred Lengths | 2 (2.000) 2 1/4 (2.250) 2 1/2 (2.500) |
- 0.18 | 98032 98036 98040 |
52032 52036 52040 |
54032 54036 54040 |
56032 56036 56040 |
58032 58036 58040 |
| 2 3/4 (2.750) 3 (3.000) 3 1/4 (3.250) |
- 0.20 | 98044 98048 98052 |
52044 52048 52052 |
54044 54048 54052 |
56044 56048 56052 |
58044 58048 58052 |
|
| 3 1/2 (3.500) 4 (4.000) 4 1/2 (4.500) |
98056 98064 98072 |
52056 52064 52072 |
54056 54064 54072 |
56056 56064 56072 |
58056 58064 58072 |
||
| 5 (5.000) 5 1/2 (5.500) 6 (6.000) |
98080 98088 98096 |
52080 52088 52096 |
54080 54088 54096 |
56080 56088 56096 |
58080 58088 58096 |
||
| Greater than (6.000) | -0.24 | ||||||
Material – Steel for the manufacture of screws shall be made by the electric furnace, induction furnace, or consumable-electrode process.
Designation C1F19A1 – 1625–1675 °F (885–913 °C), 2 hour minimum, oil or water quenched and tempered at 1300–1350 °F (704–730 °C) for 16 hours. Designation C1F19A2 – 1775–1825 °F (968–996 °C), 1 hour minimum, oil or water quenched and tempered at 1300–1350 °F (704–730 °C) for 16 hours. Finish: All surfaces free from burrs, detachable scale, fins, sharp edges, and other imperfections affecting serviceability. Finished parts shall have a maximum 63 µ inch (1.6 µm) AA on the threads, body under head fillet and bearing area.
Screw threads - American National Standard Class 2A shall be rolled after heat-treatment whenever practicable. Measured from point to last complete thread. Point - Shall be flat and chamfered from approximately 0.016 inch (0.406 mm) below the minor diameter. The length of the point shall be from 1/2 to 1 1/2 threads. Top of head - May be full form or indented at the option of the manufacturer. If full form, the top of head shall be chamfered or rounded with the diameter of chamfer circle or start of rounding being equal to the maximum width across flats, within a tolerance of minus 15 percent. If the top of head is indented, the periphery may be rounded.
When requested, the supplier shall submit promptly to the purchaser at the point of delivery a certificate of test showing the results of tests for chemical analysis and properties required by this specification. This certificate shall be addressed to the section, unit, or person specified on the purchase order, and shall contain the EMPIS designation, the purchase order number, and the quantity shipped so that the certificate may be identified with the shipment.
All machine parts shall be properly separated by size and shape for shipment and suitably packed to prevent damage or loss during transit. Each individual package or box shall be legibly marked with the manufacturers name or trade name, and either the EMPIS drawing and part number or the size and shape of the machine parts contained therein and the EMPIS designation as shown on the purchase order. Each outer container shall be legibly marked with the purchase order number, the manufacturer’s name or trade name, the size and shape of the machine parts contained therein and the EMPIS designation.
