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.

One should consider longer than standard thread lengths for lag screws which are extremely long. Unless otherwise specified, Portland Bolt manufactures nonstandard lag screw with a thread length of one-half the bolt length plus 1/2″ regardless of the length of the bolt. 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.

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
3/8 0.388 0.360 9/16 1/4 7 0.143 0.062 0.055 0.265
1/2 0.515 0.482 3/4 11/32 6 0.167 0.072 0.064 0.371
5/8 0.642 0.605 15/16 27/64 5 0.200 0.086 0.077 0.471
3/4 0.768 0.729 1-1/8 1/2 4-1/2 0.222 0.096 0.085 0.579
7/8 0.895 0.852 1-5/16 37/64 4 0.250 0.108 0.096 0.683
1 1.022 0.976 1-1/2 43/64 3-1/2 0.286 0.123 0.110 0.780
1-1/8 1.149 1.098 1-11/16 3/4 3-1/4 0.308 0.133 0.119 0.887
1-1/4 1.277 1.223 1-7/8 27/32 3-1/4 0.308 0.133 0.119 1.012
1-3/8 1.404 1.346 2-1/16 29/32 3 0.333 0.143 0.128 1.119
1-1/2 1.531 1.469 2-1/4 1 3 0.333 0.143 0.128 1.244

Dimensions per ASME B18.2.6 2003

Stock Lag Screws

Lag Screw Size Hot Dip Galvanized Part#
3/8 x 2 11384
3/8 x 2-1/2 11386
3/8 x 3 11388
3/8 x 3-1/2 11390
3/8 x 4 11392
3/8 x 5 11396
3/8 x 6 11400
3/8 x 8 11408
1/2 x 3 11418
1/2 x 4 11422
1/2 x 5 11426
1/2 x 6 11430
1/2 x 7 11434
1/2 x 8 11438
1/2 x 10 11442
1/2 x 12 11446
5/8 x 3 11454
5/8 x 4 11458
5/8 x 6 11466
5/8 x 7 11470
5/8 x 8 11472
5/8 x 10 11476
5/8 x 12 11480
3/4 x 5 11498
3/4 x 6 11502
3/4 x 8 11510
3/4 x 10 11514
3/4 x 12 11518
3/4 x 14 11522
3/4 x 18 11530
*Many other sizes available upon request