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Flat Socket Cap Screw

Selected F835 Flat Socket Head Cap Screw Alloy BlackFlat Socket Cap Screw
F835 Flat Socket Head Cap Screw Alloy BlackFlat Socket Cap Screw

ASTM F835 Flat Socket head cap screws have a countersunk head with a flat top surface and hexagonal recess. The ASTM F835 specification covers the requirements for quenched and tempered alloy steel hexagon flat countersunk head cap screws, having material properties for high-strength requirements. Dimensional specifications are governed by ASME B18.3. Flat socket head cap screws are commonly used in applications in which it is necessary to recess the head of the fastener flush with the surface.

Products

Mechanical Properties

Quenched & Tempered Alloy Steel Per ASTM F835-16
Nominal
Diameter		 Full-Size Screws Machined Test Specimen Product Hardness
Tensile
Strength		 Yield Strength
at 0.2% offset		 Tensile
Strength		 Elongation
in 4D		 Reduction
of Area		 Rockwell C Vickers DPH
ksi ksi ksi % %
1/2" & under 145 min (1) (1) (1) (1) 39-44 382-434
over 1/2" 135 min 153 min 170 min 8 min 35 min 37-44 363-434
  1. 1. Not applicable.

Governing Standards

ASTM F835 This specification covers the requirements for quenched and tempered alloy steel hexagon socket button (SBHCS) 0.060 through 0.625 thread sizes and flat countersunk (SFHCS) 0.060 through 1.5 thread sizes head cap screws having material properties for high-strength requirements.
ASME B18.3 Covers the complete general and dimensional data for various types of hexagon socket cap screws, shoulder screws, set screws, and hexagon keys recognized as an American National Standard.
ASME B1.1 UNC & UNF Class 2A Specifies the thread form, series, class, allowance, tolerance, and designation for unified screw threads.

Alloy Steel Flat Socket Cap Screw Head Marking
Alloy Steel Flat Socket Cap Screw requires no material marking

Chemical Properties

Per ASTM F835-16
Material Heat Analysis Product Analysis
Carbon Phosphorus Sulfur Alloying
Elements		 Carbon Phosphorus Sulfur Alloying
Elements
% by weight % by weight % by weight % by weight % by weight % by weight
Quenched and tempered alloy steel 0.30 to 0.48 0.035 max 0.040 max (1) 0.28 to 0.50 0.040 max 0.045 max (1)
  1. 1. One or more of the following alloying elements, chromium, nickel, molybdenum, or vanadium, shall be present in the steel in sufficient quantity to ensure the specific strength properties are met after oil quenching and tempering. The steel shall meet the AISI definition of alloy steel, that is, maximum and minimum element content requirement or minimum element limits specified.

Dimensional Specifications

Alloy Steel Flat Socket cap screw dimensions
Per ASME B18.3-2012
Size Nominal UNC UNF D A G P H J T LT
Body Head Diameter Protrusion
Gage Diameter		 Protrusion Head
Height		 Hex Socket Size Key
Engagement		 Thread Length
Max Min Max Min Max Min Max Min   Fraction Decimal Min Min Max
#0 0.0600   80 0.0600 0.0568 0.1380 0.1170 0.0780 0.0770 0.0360 0.0260 0.0440 …. 0.0350 0.0250 0.5000 0.6200
#1 0.0730 64 72 0.0730 0.0695 0.1680 0.1430 0.1010 0.1000 0.0400 0.0280 0.0540 …. 0.0500 0.0310 0.6200 0.7700
#2 0.0860 56 64 0.0860 0.0822 0.1970 0.1630 0.1240 0.1230 0.0430 0.0310 0.0640 …. 0.0500 0.0380 0.6200 0.8000
#3 0.0990 48 56 0.0990 0.0949 0.2260 0.1930 0.1480 0.1470 0.0460 0.0330 0.0730 1/16 0.0620 0.0440 0.6200 0.8300
#4 0.1120 40 48 0.1120 0.1075 0.2550 0.2180 0.1720 0.1710 0.0490 0.0360 0.0890 1/16 0.0620 0.0550 0.7500 0.9900
#5 0.1250 40 44 0.1250 0.1202 0.2810 0.2400 0.1960 0.1950 0.0510 0.0370 0.0900 5/64 0.0780 0.0610 0.7500 1.0000
#6 0.1380 32 40 0.1380 0.1329 0.3070 0.2630 0.2200 0.2190 0.0520 0.0370 0.0970 5/64 0.0780 0.0660 0.7500 1.0500
#8 0.1640 32 36 0.1640 0.1585 0.3590 0.3110 0.2670 0.2660 0.0550 0.0390 0.1120 3/32 0.0940 0.0760 0.8750 1.1900
#10 0.1900 24 32 0.1900 0.1840 0.4110 0.3590 0.3130 0.3120 0.0580 0.0410 0.1270 1/8 0.1250 0.0870 0.8750 1.2700
#12 0.2120 24 28 0.2160 0.2095 0.4500 0.4100 0.3600 0.3590 0.0690 0.0420 0.1350 1/8 0.1250 0.0940 1.0000 1.3300
1/4 0.2500 20 28 0.2500 0.2435 0.5310 0.4800 0.4240 0.4230 0.0640 0.0430 0.1610 5/32 0.1560 0.1110 1.0000 1.5000
5/16 0.3125 18 24 0.3125 0.3053 0.6560 0.6000 0.5390 0.5380 0.0700 0.4700 0.1980 3/16 0.1880 0.1350 1.1250 1.7100
3/8 0.3750 16 24 0.3750 0.3678 0.7810 0.7200 0.6530 0.6520 0.0760 0.0500 0.2340 7/32 0.2190 0.1590 1.2500 1.9400
7/16 0.4375 14 20 0.4375 0.4294 0.8440 0.7810 0.6900 0.6890 0.0920 0.0630 0.2340 1/4 0.2500 0.1590 1.3750 2.1700
1/2 0.5000 13 20 0.5000 0.4919 0.9380 0.8720 0.7390 0.7380 0.1190 0.0870 0.2510 5/16 0.3120 0.1720 1.5000 2.3800
5/8 0.6250 11 18 0.6250 0.6163 1.1880 1.1120 0.9620 0.9610 0.1350 0.0960 0.3240 3/8 0.3750 0.2200 1.7500 2.8200
3/4 0.7500 10 16 0.7500 0.7406 1.4380 1.3550 1.1860 1.1850 0.1500 0.1050 0.9600 1/2 0.5000 0.2200 2.0000 3.2500
7/8 0.8750 9 14 0.8750 0.8647 1.6880 1.6040 1.4110 1.1410 0.1650 0.1180 0.4680 9/16 0.5620 0.2480 2.2500 3.6900
1 1.0000 8 14 1.0000 0.9886 1.9380 1.8410 1.6350 1.6340 0.1810 0.1300 0.5400 5/8 0.6250 0.2970 2.5000 4.1200
1 1/8 1.1250 7 12 1.1250 1.1086 2.1880 2.0790 1.8590 1.8580 0.1960 0.1400 0.6110 3/4 0.7500 0.3250 2.8100 4.6500
1 1/4 1.2500 7 12 1.2500 1.2336 2.4380 2.3160 2.0830 2.0820 0.2120 0.1500 0.6830 7/8 0.8750 0.3580 3.1200 5.0900
1 3/8 1.3750 7 12 1.3750 1.3568 2.6880 2.5530 2.3060 2.3050 0.2280 0.1620 0.7550 7/8 0.8750 0.4020 3.4400 5.6500
1 1/2 1.5000 6 12 1.5000 1.4818 2.9380 2.7910 2.5300 2.5290 0.2430 0.1730 0.8270 1 1.0000 0.4350 3.7500 6.0800
  1. All dimensions are in inches.