Specification Sheet

342
SOCKETS
Socket Flat Head cap ScrewS - alloy Steel
ASME B18.3-2012,
Blue Devil®
Nominal
Size
D A H G P J T F
Tensile
Strength,
Lbs.
Single
Shear
Strength
of Body
Recommended
Seating Torques,
in./lbs.
Body
Diameter
Head
Diameter
Head
Height
Protrusion
Gage
Diameter
Protrusion
Hex
Socket
Size
Key En-
gagement
Fillet
Transi-
tion
Diam.
Max Min
Theoretical
Sharp Max
Abs.
Min
Ref Max Min Max Min Nom Min Max Min lbs., Min
Coarse
Thread
Fine
Thread
4 0.1120 0.1075 0.255 0.218 0.083 0.172 0.171 0.057 0.036 1/16 0.055 0.136 880 950 8. 8.
5 0.1250 0.1202 0.281 0.240 0.090 0.196 0.195 0.059 0.037 5/64 0.061 0.153 1150 1,150 12. 13.
6 0.1380 0.1329 0.307 0.263 0.097 0.220 0.219 0.060 0.037 5/64 0.066 0.168 1320 1,400 15. 17.
8 0.1640 0.1585 0.359 0.311 0.112 0.267 0.266 0.063 0.039 3/32 0.076 0.194 2030 2,000 30. 31.
10 0.1900 0.1840 0.411
0.359 0.127 0.313 0.312 0.066 0.041 1/8 0.087 0.220 2540 2,700 40. 45.
1/4 0.2500 0.2435 0.531 0.480 0.161 0.424 0.423 0.072 0.043 5/32 0.111 0.280 4610 4,700 100. 110.
5/16 0.3125 0.3053 0.656 0.600 0.198 0.539 0.538 0.078 0.047 3/16 0.135 0.343 7600 7,360 200. 220.
3/8 0.3750 0.3678 0.781 0.720 0.234 0.653 0.652 0.088 0.050 7/32 0.159 0.405 11,200 10,600 350. 400.
7/16 0.4375 0.4294 0.844 0.781 0.234 0.690 0.689 0.104 0.063 1/4 0.159 0.468 15,400 14,400 560. 625.
1/2 0.5000 0.4919 0.938 0.872 0.251 0.739 0.738 0.131 0.087 5/16 0.172 0.530 20,600 18,850 850. 1,000.
5/8 0.6250 0.6163 1.188 1.112 0.324 0.962 0.961 0.146 0.096 3/8 0.220 0.655 30,500 29,450 1,700. 1,900.
3/4 0.7500 0.7406 1.438 1.355 0.396 1.186 1.185 0.170 0.105 1/2 0.220 0.780 45,100 42,400 3,000 3,200.
Tolerance on Length
Nominal Screw Size
Nominal Screw Length
Up to 1 in., Incl.
Over 1 in. to 2-1/2 in.,
Incl.
Over 2-1/2 in. to
6 in., Incl.
0 thru 3/8, Inclusive -0.03 -0.04 -0.06
7/16 thru 3/4, Inclusive -0.03 -0.06 -0.08
Description
Similar in design to a socket button head cap screw but with an 82° countersunk at head.
Applications/
Advantages
Used when a ush mounting, high strength screw is required. Commonly used in tools and dies where moving parts pass over the fastened area.
Material
Screws shall be made from an alloy steel which conforms to the following chemical composition requirements (per product analysis)--
Carbon : 0.28 to 0.50%; Phosphorus : 0.040% maximum; Sulfur : 0.045% maximum. Also, one or more of the following elements shall be present in
sufcient quantity to meet the performance requirements listed below: chromium, nickel, molybdenum or vanadium.
Heat Treatment
Screws shall be heat treated by oil quenching from above the transformation temperature and then tempered at a temperature not lower than 650°F.
Hardness
Thru 1/2” diam.: Rockwell C 39 - 44; Over 1/2” diam.: Rockwell C 37 - 44
Tensile Strength
Thru 1/2” diam.: 145,000 psi. minimum; Over 1/2” diam.: 135,000 psi. minimum
Yield Strength
153,000 psi. minimum (over 1/2” diam.)
Elongation
8% minimum (applies to machined specimens over 1/2” diam., of length at least 4D where D equals the nominal diameter of the screw)”
Reduction of Area
35% minimum (applies to machined specimens over 1/2” diam.)
Finish
Screws are supplied plain.
Blue Devil
®
is a registered trademark of the Safety Socket Screw Corporation.
FLAT HEAD CAP SCREWS
Alloy Steel