Countersunk Bolts

Countersunk bolts are used when a smooth surface is required. Common applications include: bridge decking, walkways, and railing.

MANUFACTURING

Portland Bolt manufactures countersunk bolts from 1/2” diameter through 1-1/2” diameter in most ASTM, AASHTO, and SAE specifications including, A307 Grade A, A449, and Grade 8. Countersunk bolts have a head angle of approximately 80 degrees. Bolts are available with and without a slot in the head. Special tooling can be created to produce nonstandard head dimensions or bolt heads with your company’s name and/or logo.

STANDARD THREAD LENGTH

Bolt lengths ≤ 6”: Thread length = (2 X diameter) + 1/4”
Bolt lengths > 6”: Thread length = (2 X diameter) + 1/2”
Note: Most stock hex bolts longer than 12” in length will have 6” of thread.

Bolt Diameter	D	F			H
	Body Diameter	Head Diameter			Head Height
	Max	Max Edge Sharp	Min Edge Sharp	Absolute Min Rounded	Max	Min
1/2	0.515	0.935	0.905	0.845	0.269	0.233
5/8	0.642	1.169	1.132	1.066	0.336	0.292
3/4	0.768	1.402	1.357	1.285	0.403	0.349
7/8	0.895	1.637	1.584	1.511	0.470	0.408
1	1.022	1.869	1.810	1.735	0.537	0.466
1-1/8	1.149	2.104	2.037	1.962	0.604	0.525
1-1/4	1.277	2.337	2.262	2.187	0.671	0.582
1-3/8	1.404	2.571	2.489	2.414	0.738	0.641
1-1/2	1.531	2.804	2.715	2.640	0.805	0.698

Dimensions per ASME B18.5 1990 (R 1998)

Specifications:
- ASTM A307
- ASTM A449
Technical:
- Bolt Shear Strength
- Welding to High Strength Fasteners
Industrial Applications:
- OEM
- Highway
- Mining