Hex bolts (six sided heads) are the industry standard for fasteners with forged heads. ASTM A307  grade A bolts, all SAE hex bolts, and several other common specifications require a standard (finished) hex head. For specifications such as A307 grade B, A325 and A490 that require a heavy hex pattern, refer to dimensional tolerances for heavy hex bolts or structural bolts.

Manufacturing

Portland Bolt manufactures lag screws from 1/2″ diameter through 1-1/2″ diameter in most ASTM, AASHTO, and SAE specifications. Special tooling can be created to produce nonstandard head dimensions or bolt heads with your company’s name and/or logo.

Unless otherwise specified, nonstandard lag screws manufactured by Portland Bolt will possess a semi-cone point rather than a gimlet or cone point. A full point is unnecessary since a pilot hole nearly as large as the root diameter of the lag screw will need to be drilled prior to installation. Additionally, a gimlet point is designed for small diameter screws so they can be installed without a pilot hole. Lag screws in diameters listed in the above table do not require a gimlet point since too much torque would be required to install the large screws without drilling a pilot hole first. Without a pilot hole, the heads of the screws will often break before the lag is properly installed.

Stock

Diameters: 1/2″ – 3/4″
Lengths: 18″ maximum
Origin: Import
Finish: Black and hot-dip galvanized

Standard Thread Length

The minimum thread length shall be equal to one-half the nominal screw length plus 1/2″ or 6”, whichever is less. One should consider longer than standard thread lengths for lag screws which are extremely long.

Note: Hex lag screws larger than 3/4″ in diameter and all square lag screws are rarely available in the marketplace as a stock item.

Hex Lag Dimensions

Click table to show drawinghex-lag
Bolt Diameter D F H Threads Per Inch Thread Dimension
Body Diameter Width Across Flats Head Height Pitch TF TD TR
Max Min Flat At Root Depth of Thread Root Diameter
12 0.515 0.482 34 1132 6 0.167 0.072 0.064 0.371
58 0.642 0.605 1516 2764 5 0.200 0.086 0.077 0.471
34 0.768 0.729 118 12 412 0.222 0.096 0.085 0.579
78 0.895 0.852 1516 3764 4 0.250 0.108 0.096 0.683
1 1.022 0.976 112 4364 312 0.286 0.123 0.110 0.780
118 1.149 1.098 11116 34 314 0.308 0.133 0.119 0.887
114 1.277 1.223 178 2732 314 0.308 0.133 0.119 1.012
138 1.404 1.346 2116 2932 3 0.333 0.143 0.128 1.119
112 1.531 1.469 214 1 3 0.333 0.143 0.128 1.244
Dimensions per ASME B18.2.6 2003

Stock Lag Screws

Length (in.) Diameter
3/8" 1/2" 5/8" 3/4"
Galvanized
2 11384 - - -
212 11386 - - -
3 11388 11418 11454 -
312 11390 - - -
4 11392 11422 11458 -
5 11396 11426 - 11498
6 11400 11430 11466 11502
7 - 11434 11470 -
8 11408 11438 11472 11510
10 - 11442 11476 11514
12 - 11446 11480 11518
14 - - - 11522
18 - - - 11530
Other sizes and finishes available on request.