Carriage bolts (round head with square neck) are commonly used in wood connections. The square neck under the round head will seat into the hole in the wood to prevent the head from turning. Because they are used with wood, carriage bolts are rarely high strength and virtually always supplied in a standard ASTM A307 specification.


Manufacturing:

Fastindo Wiratama manufactures carriage bolts from 1/2″ diameter through 1-1/4″ diameter in most ASTM, AASHTO, and SAE specifications. Special tooling can be created to produce nonstandard head dimensions, carriage bolts larger than 1″ in diameter, 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″

Stock:

Diameters: 3/8″ – 3/4″
Lengths: 18″ maximum
Origin: Import
Finish: Black and hot-dip galvanized


Carriage Dimensions
Bolt Diameter D C H P F
Body Diameter Head Diameter Head Height Square Width Square Depth
Max Min Max Min Max Min Max Min Max Min
1⁄2 0.515 0.483 1.094 1.032 0.270 0.250 0.515 0.492 0.281 0.250
5⁄8 0.642 0.605 1.344 1.219 0.344 0.313 0.642 0.616 0.344 0.313
3⁄4 0.768 0.729 1.594 1.469 0.406 0.375 0.768 0.741 0.406 0.375
7⁄8 0.895 0.852 1.844 1.719 0.469 0.438 0.895 0.865 0.469 0.438
1 1.022 0.976 2.094 1.969 0.531 0.500 1.022 0.990 0.531 0.500
11⁄4* 1.277 2.850 0.531 0.500 1.250 0.625
*Dimensions per ASME B18.5 1990 (R 1998) cover diameters up to 1". Bolts over 1" use custom head dimensions.

Stock Carriage Bolts
Length (in.) Diameter
3/8" 1/2"
Galvanized
3 - 19060
4 - 19065
6 19026 19074
8 19033 19082
These sizes are readily available in the marketplace and Fastindo Wiratama stocks many of them in varying quantities. If you require a size that is not listed, Fastindo Wiratama will manufacture them.