With six sided heads, Hex bolts boast of being the industry standard as far as fasteners with forged heads are concerned. ASTM A307 grade A bolts, SAE hex bolts, and numerous other common specifications demand a standard hex head. When it comes to specifications like A307 grade B, A325 & A490 which demand a heavy hex pattern, it is ideal to refer dimensional tolerances for structural bolts or heavy hex bolts.

Manufacturing

Baseline Bolt manufactures lag screws of diameter 1/2″ - 1-1/2″ in most of the ASTM, AASHTO, & SAE specifications. It is possible to create special tooling so as to produce nonstandard bolt heads or head dimensions with the name and/or logo of your company.

Well, if not specified, the nonstandard lag screws that are manufactured by Baseline Bolt will have a semi-cone point instead of a gimlet or a cone point. It is important to have a full point because a pilot hole that is as big as the lag screw’s root diameter has to be drilled before installation. Besides, for small diameter screws, a gimlet point is also designed so that installation without a pilot hole is possible. Lag screws in above listed diameters don’t generally require a gimlet point because too much torque is required for installing large screws without having to drill a pilot hole first. If there isn’t a pilot hole, heads of the screws tend to break often prior to the proper installation of the lag.

Stock

Diameters: 1/2″ – 3/4″
Lengths: 18″ maximum
Origin: Import
Finish: Plain 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 drawing
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
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 11⁄8 1⁄2 41⁄2 0.222 0.096 0.085 0.579
7⁄8 0.895 0.852 15⁄16 37⁄64 4 0.250 0.108 0.096 0.683
1 1.022 0.976 11⁄2 43⁄64 31⁄2 0.286 0.123 0.110 0.780
11⁄8 1.149 1.098 111⁄16 3⁄4 31⁄4 0.308 0.133 0.119 0.887
11⁄4 1.277 1.223 17⁄8 27⁄32 31⁄4 0.308 0.133 0.119 1.012
13⁄8 1.404 1.346 21⁄16 29⁄32 3 0.333 0.143 0.128 1.119
11⁄2 1.531 1.469 21⁄4 1 3 0.333 0.143 0.128 1.244
Dimensions per ASME B18.2.1 2003

Stock Lag Screws

Length (in.) Diameter
3/8" 1/2" 5/8" 3/4"
Plain Galv. Plain Galv. Plain Galv. Plain Galv.
1 11375 11376 - - - - - -
11⁄4 11377 11378 - - - - - -
11⁄2 11379 11380 18904 18905 - - - -
13⁄4 11381 11382 - - - - - -
2 11383 11384 11413 11414 11447 11448 - -
21⁄2 11385 11386 11415 11416 11449 11450 - 19575
3 11387 11388 11417 11418 11453 11454 11489 11490
31⁄2 11389 11390 11419 11420 11455 11456 11491 11492
4 11391 11392 11421 11422 11457 11458 11493 11494
41⁄2 11393 11394 11423 11424 11459 11460 - -
5 11395 11396 11425 11426 11461 11462 11497 11498
51⁄2 11397 11398 18906 18907 18908 18909 - -
6 11399 11400 11429 11430 11465 11466 11501 11502
7 11403 11404 11433 11434 11469 11470 11505 11506
8 11407 11408 11437 11438 11471 11472 11509 11510
9 - - 11439 11440 11473 11474 11511 11512
10 11411 11412 11441 11442 11475 11476 11513 11514
11 - - - - 18910 18911 18913 18914
12 18902 18903 11445 11446 11479 11480 11517 11518
14 - - 18266 18267 11481 11482 11521 11522
16 - - 18268 18269 19597 19545 11525 11526
18 - - 18270 18271 19693 19694 11529 11530
20 - - - - - - 18915 18916
These sizes are readily available in the marketplace and baseline Bolt stocks many of them in varying quantities. If you require a size that is not listed, baseline Bolt will manufacture them.