Home > Fasteners > Socket Screws & Fasteners > 18-8 SS Flat Socket Cap Screw

Enlarge

18-8 SS Flat Socket Cap Screw

ASTM F879 stainless flat socket head cap screws have a countersunk head with a flat top surface and hexagonal recess. The ASTM F879 specification covers the requirements for stainless steel hexagon flat countersunk head cap screws for use in applications requiring general corrosion resistance. Dimensional specifications are governed by ASME B18.3. Stainless 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. Stainless steel fasteners are commonly used in applications that require general atmospheric corrosion resistance, such as chemical and food processing equipment. Stainless steel has a higher corrosion resistance than carbon steel.

Products
Governing Standards
Mechanical Properties
Chemical Properties
Dimensional Specifications

Dimensional Specifications

Dimensional SpecificationsStainless Steel Flat Socket Cap Screw

Per ASME B18.3-2012
Size	Nominal	UNC	UNF	D		A		G		P		H	J		T	L
				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

All dimensions are in inches.

18-8 SS Flat Socket Cap Screw

of 1

Sort By

View

Item # Availability Price Quantity UOM

SFLS0310075

In Stock

$0.35647/EA

See Quantity Discounts

5/16-18 X 3/4 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

$0.35647/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
1	$0.35647/ EA
550	$0.33237/ EA
2170	$0.31386/ EA
9730	$0.2135/ EA

SFLS0310100

In Stock

$0.27934/EA

See Quantity Discounts

5/16-18 X 1 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

$0.27934/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
1	$0.27934/ EA
450	$0.26046/ EA
1780	$0.24594/ EA
8000	$0.16731/ EA

SFLS0310125

In Stock

$0.83817/EA

See Quantity Discounts

5/16-18 X 1 1/4 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

$0.83817/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
1	$0.83817/ EA
370	$0.78152/ EA
1470	$0.73798/ EA
6600	$0.50201/ EA

SFLS0310150

In Stock

$0.39648/EA

See Quantity Discounts

5/16-18 X 1 1/2 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

$0.39648/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
1	$0.39648/ EA
330	$0.36968/ EA
1320	$0.34908/ EA
5930	$0.23747/ EA

SFLS0310175

In Stock

$0.59768/EA

See Quantity Discounts

5/16-18 X 1 3/4 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

$0.59768/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
1	$0.59768/ EA
290	$0.55728/ EA
1140	$0.52623/ EA
5130	$0.35798/ EA

SFLS0310200

In Stock

$0.43777/EA

See Quantity Discounts

5/16-18 X 2 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

$0.43777/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
1	$0.43777/ EA
250	$0.40818/ EA
970	$0.38544/ EA
4340	$0.2622/ EA

ASTM F879	This specification covers the chemical and mechanical requirements for stainless steel inch hexagon socket button (SBHCS) and flat countersunk (SFHCS) head cap screws with nominal thread 0.060 through 0.625 in. intended for use in applications requiring general corrosion resistance.
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.

Austenitic Stainless Steel		Per ASTM F879-15
Alloy Condition CW	Full-Size Product Tests (1)		Machined Specimen Tests			Core Hardness (2)
	Tensile Strength	Extension (3)	Tensile Strength	Yield Strength	Elongation	Vickers	Rockwell
	ksi	Min	ksi	ksi	% Min
	80 min	0.4D	80 min	40 min	25	150 min	50 HRA min

Per ASTM F879-15
Material	Carbon	Manganese	Phosphorus	Sulfur	Silicon	Chromium	Nickel	Copper
Material	% by weight	% by weight	% by weight	% by weight	% by weight	% by weight	% by weight	% by weight
Alloy Group 1, UNS S30400	0.08	2.00	0.045	0.030	1.00	18.0 to 20.0	8.0 to 10.5	1.00

18-8 SS Flat Socket Cap Screw

Technical Data

Governing Standards

Governing StandardsStainless Steel Flat Socket Cap Screw

Mechanical Properties

Mechanical PropertiesStainless Steel Flat Socket Cap Screw

Chemical Properties

Chemical PropertiesStainless Steel Flat Socket Cap Screw

Dimensional Specifications

Dimensional SpecificationsStainless Steel Flat Socket Cap Screw

You've Selected

Grade

Diameter

Length

Threading

5/16-18 X 3/4 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

5/16-18 X 1 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

5/16-18 X 1 1/4 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

5/16-18 X 1 1/2 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

5/16-18 X 1 3/4 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW

5/16-18 X 2 F879 18-8 STAINLESS STEEL FLAT SOCKET CAP SCREW