Hex Lag Screw

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How we deliver:

Hex lag screws feature six-sided heads and are regarded as an industry standard for strength and reliability. Many fasteners—including ASTM A307 Grade A bolts and SAE hex bolts—require a standard hex head. For specifications such as A307 Grade B, A325, and A490, which call for a heavy hex pattern, it is essential to refer to the dimensional tolerances for structural and heavy hex bolts to ensure proper compliance and performance.

Manufacturing

EBB manufactures superior-quality lag screws in diameters ranging from 1/2″ to 1-1/2″, meeting most ASTM, SAE, and AASHTO specifications. We also offer custom manufacturing through special tooling to produce non-standard bolt heads and head dimensions with your preferred logo and/or company name.

Non-standard lag screws manufactured by BBI typically feature a semi-cone point rather than a full cone point or gimlet point. For proper installation, a pilot hole equal to the root diameter of the lag screw must be drilled beforehand. Gimlet points are generally designed only for small-diameter screws to allow installation without a pilot hole.

Lag screws within the above-mentioned diameters do not require a gimlet point, as installing large-diameter screws without a pilot hole demands excessive torque. In such cases, the absence of a pilot hole often results in head failure before proper installation.

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	T^F	T^D	T^R
	Max	Min	Width Across Flats	Head Height		Pitch	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.