Smith Fasteners Smitty Smith Fastener Logo Smith Fasteners Smitty

Link to Home PageLink to our Showroom LobbyLink To the Table of ContentsClick here to Contact Smith Fastener
Link to Self Tapping ScrewsLink to Machine ScrewsLink to All of the Bolts
Hex Head Cap Screws

Grade-5 Hex Cap Screw Mechanicals & Performance Data  Grade-8 Hex Cap Screw Mechanicals & Performance Data
Grades 2 and Stainless Steel Hex Cap Screw Information


Hex Head Cap Screw images
Grade-5 & Grade-8 Hex Head Cap Screws   ASME B18.2.1  1996
Nominal or
Basic Product
Diameter
E F G H J LT Y
Body Diameter Width Across Flats Width
Across
Corners
Head Height Wren-
ching
Height
Thread Length Transi-
tion
Thread
Length
Screws
Less or
Equal to
6 inch
Screws
More
Than
6 inch
Max Min Basic Max Min Max Min Basic Max Min Min Ref Ref Max
1/4 .250 .250 .245 7/16 .438 .428 .505 .488 5/32 .163 .150 .106 .750 1.000 .250
5/16 .3125 .3125 .3065 1/2 .500 .489 .577 .557 16/64 .211 .0195 .140 .875 1.125 .278
3/8 .375 .375 .369 9/16 .562 .551 .650 .628 15/64 .243 .226 .160 1.000 1.250 .312
7/16 .4375 .4375 .4305 5/8 .625 .612 .722 .698 9/32 .291 .272 .195 1.125 1.375 .357
1/2 .500 .500 .493 3/4 .750 .736 .866 .840 5/16 .323 .302 .215 1.250 1.500 .385
9/16 .5625 .5625 .5545 13/16 .812 .798 .938 .910 23/64 .371 .348 .250 1.375 1.625 .417
5/8 .625 .625 .617 15/16 .938 .922 1.083 1.051 25/64 .403 .378 .269 1.500 1.750 .455
3/4 .750 .750 .741 1-1/8 1.125 1.100 1.299 1.254 15/32 .483 .455 .324 1.750 2.000 .500
7/8 .875 .875 .866 1-5/16 1.312 1.285 1.516 1.465 35/64 .563 .531 .378 2.000 2.250 .556
1 1.000 1.000 .990 1-1/2 1.500 1.469 1.732 1.675 39/64 .627 .591 .416 2.250 2.500 .625
1-1/8 1.125 1.125 1.114 1-11/16 1.688 1.631 1.949 1.859 11/16 .718 .658 .461 2.500 2.750 .714
1-1/4 1.250 1.250 1.239 1-7/8 1.875 1.812 2.165 2.066 25/32 .813 .749 .530 2.750 3.000 .714
1-1/2 1.500 1.500 1.488 2-1/4 2.250 2.175 2.598 2.480 1-5/16 .974 .902 .640 3.250 3.500 .833

Tolerance on Length Nominal Screw Size Nominal Screw Length
Up to 1 in.
Inclusive
Over 1 in. to
2-1/2 in. Incl.
Over 2-1/2 in. to
4 in. Incl.
Over 4 in. to
6 in. Incl.
Longer than
6 inch.
1/4 to 3/8 -.03 -.04 -.06 -.10 -.18
7/16 to 1/2 -.03 -.06 -.08 -.10 -.18
9/16 to 3/4 -.03 -.08 -.10 -.10 -.18
7/8 to 1 - -.10 -.14 -.16 -.20
1-1/8 to 1-1/2 - -.12 -.16 -.18 -.22


Head Markin Image Mechanical & Performance Data
for Grade-5 Hex Head Cap Screws
Head Marking Image

Description A cap screw made from medium carbon steel and heat treated.
Applications
and
Advantages
Has greater tensile strength than a Grade-2. Yield-to-tensile ratio is the lowest of all heat treated steels.
Material Medium carbon steel. Use of an alloy steel is acceptable.
Heat Treatment Grade-5 cap screws shall be heat treated, oil or water quenched, at manufacturers option, and tempered at a minimum tempering temperature of 800°F.
Core Hardness 1/4 thru 1 inch diameter:  Rockwell C25 - C34
1-1/8 thru 1-1/2 in. diameter:  Rockwell C19 - C30
Surface Hardness 1/4 thru 1 inch diameter:  Rockwell 30N54 maximum
1-1/8 thru 1-1/2 in. diameter:  Rockwell 30N50 maximum
Proof Load 1/4 thru 3/4 in. diameter, 6 in. and shorter:  55,000 psi
1/4 thru 3/4 in. diameter, over 6 in. in length:  33,000 psi
7/8 thru 1-1/2 in. diameter:  33,000 psi
Yield
Strength
1/4 thru 1 inch diameter:  92,000 psi
1-1/8 thru 1-1/2 inch diameter:  81,000 psi
Tensile
Strength
1/4 thru 1 inch diameter:  120,000 psi
1-1/8 thru 1-1/2 inch diameter:  105,000 psi
Elongation* 14% minimum
Reduction
of Area
35% minimum
Plating See plating page for plating information
* These properties are tested only on machined specimens when the testing machine cannot provide for full testing of the parts.
Note: Product standards require the manufacturer's head marking to appear on the top of all cap screws 1/4 inch diameter and larger. The X on the head image above represents a location that such marking may appear.
Note: The length (L) of a cap screw is measured from the under-head bearing area to the extreme end of the screw.
Return to top of page

Head Marking Image Mechanical & Performance Data
for Grade-8 Hex Head Cap Screws
Head Marking Image

Description A cap screw made from medium carbon alloy steel and heat treated.
Applications
and
Advantages
Has a greater tensile strength tha a Grade-5. designed for use in high stress applications where strength or safety is an issue. See specs below for more info on how the Grade-8 exceeds the strength of a Grade-5.
Material Medium carbon alloy steel. Note:  For diameters 1/4 thru 7/16 inch, it is permissible to use AISI 1541 steel.
Heat Treatment Grade-8 cap screws shall be heat treated, oil quenched and tempered at a minimum of 800°F.
Surface Hardness 1/4 thru 1-1/2 inch diameter:  Rochwell 30N58.6 maximum
Core Hardness 1/4 thru 1-1/2 inch diameter:  Rockwell C33 - C39
Yield Strength* 1/4 thru 1-1/2 diameter:  130,000 psi minimum
Tensil Strength* 1/4 thru 1-1/2 diameter:  150,000 psi minimum
Elongation* 12% minimum
Reduction of Area 35% minimum
Proof Load 1/4 thru 1-1/2 inch diameter:  120,000 psi
Plating See plating page for plating information
* These properties are tested only on machined specimens when the testing machine cannot provide for full testing of the parts.
Note: Product standards require the manufacturer's head marking to appear on the top of all cap screws 1/4 inch diameter and larger. The X on the head images above represents a location that such marking may appear.
Note: The length (L) of a cap screw is measured from the under-head bearing area to the extreme end of the screw.
Return to top of page

Home Product Showroom Table of Contents Contact Smith Fastener


Smith Fastener Company, A California Corporation - 3613 East Florence Avenue, Bell, California, 90201 - Phone: ( 323 ) 587-0382 and ( 800 ) 764-8488 - FAX: ( 323 ) 587-8712 - E-mail: sales@smithfast.com - Copyright © 2004 by Smith Fastener Company - Please report website problems to: WebMaster - Last updated: October 27th, 2004
http://www.smithfast.com/hexcapscrews5_8.html