Durable Screw Lag Square Head Steel Black Oxide

Xiaoguo® supplies Durable Screw Lag Square Head Steel Black Oxide – square head grips a wrench without slipping; coarse threads bite deep into wood. Perfect for timber frames, decks, and heavy woodwork. Ask for a Price list.

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Product Description

Durable Screw Lag Square Head Steel Black Oxide with manufacturer Xiaoguo® are thick wooden screws with square heads, specifically designed to fix heavy components onto wood.Its head is square-shaped, and the screw has very wide and deep threads. The tail is pointed.They are much thicker and stronger than ordinary wooden screws. They are commonly used for building wooden houses, laying railway sleepers, and fixing the bases of large equipment, etc.

The square-head design can withstand high torque without slipping, and is suitable for heavy wooden structures and mechanical base fixation.Supports non-standard customization: diameter; length; thread length; edge dimension of the head; materials available include carbon steel, stainless steel, brass, etc.; surface treatment can also be selected based on the actual usage environment.

Durable Screw Lag Square Head Steel Black Oxide

Structural decomposition

What does it look like?

The structure of a Durable Screw Lag Square Head Steel Black Oxide consists of four parts: the head, the rod, the thread and the tip.

1.Head

Square shape, with sharp corners on all four sides. The dimensions of opposite sides are in accordance with the standard. The height of the head is approximately 0.6–0.7 times the diameter of the screw. The bottom surface is flat. During installation, it can usually be used in conjunction with flat washers to distribute the pressure and prevent the head from sinking into the wood.

2.Rod

The shaft part is divided into two sections. The section near the head has no threads and its length accounts for approximately 1/3 to 1/2 of the total length of the screw; the rest is threaded.

3.Thread

Coarse wood thread, with a larger pitch than that of ordinary mechanical screws. The thread is deeper and the thread points are sharper, facilitating penetration into the wood fibers.

4.tip

Conical, with a cone angle of approximately 30°–45°. When screwing into the hole, the tip guides the Durable Screw Lag Square Head Steel Black Oxide to remain vertical, preventing it from being twisted.

Durable Screw Lag Square Head Steel Black Oxide

Mon	#10	1/4	5/16	3/8	1/2	5/8	3/4	7/8	1	1-1/8	1-1/4
P	11	10	9	7	6	5	4.5	4	3.5	3.25	3.25
d max	0.199	0.26	0.324	0.388	0.515	0.642	0.768	0.895	1.022	1.149	1.277
d min	0.178	0.237	0.298	0.36	0.482	0.605	0.729	0.852	0.976	1.1	1.223
d1 max	0.122	0.177	0.228	0.268	0.374	0.473	0.582	0.686	0.784	0.892	1.017
d1 min	0.107	0.16	0.21	0.25	0.354	0.453	0.562	0.665	0.76	0.867	0.987
ds max	0.199	0.26	0.324	0.388	0.515	0.642	0.768	0.895	1.022	1.149	1.277
ds min	0.178	0.237	0.298	0.36	0.482	0.605	0.729	0.852	0.976	1.098	1.223
s max	0.281	0.375	0.5	0.562	0.75	0.938	1.125	1.312	1.5	1.688	1.875
s min	0.271	0.362	0.484	0.544	0.725	0.906	1.088	1.269	1.45	1.631	1.812
e max	0.398	0.53	0.707	0.795	1.061	1.326	1.591	1.856	2.121	2.386	2.652
e min	0.372	0.498	0.665	0.747	0.995	1.244	1.494	1.742	1.991	2.239	2.489
k max	0.14	0.188	0.22	0.268	0.348	0.444	0.524	0.62	0.684	0.78	0.876
k min	0.11	0.156	0.186	0.232	0.308	0.4	0.476	0.568	0.628	0.72	0.812
r max	0.03	0.03	0.03	0.03	0.03	0.06	0.06	0.06	0.09	0.09	0.09
r min	0.01	0.01	0.01	0.01	0.01	0.02	0.02	0.02	0.03	0.03	0.03

FAQ

1.Will it rust?

Yes. The black coating is very thin and mainly relies on the anti-rust oil applied through immersion. After the oil film evaporates, the carbon steel will rust. It will rust quickly in a humid environment.

2.Can custom non-standard lengths be provided?

YES. Non-standard lengths can be customized. Please confirm the drawings.

3.Is it necessary to pre-drill holes before installation?

Yes, pre-drilling is required. The diameter of the guide hole is approximately 60% - 70% of the screw diameter.

4.Can I use an impact wrench?

Yes, but it is recommended to set it to the low gear.

5.Is it necessary to use a gasket in conjunction?

It is recommended to use a flat washer. The washer can distribute the pressure and prevent the square head from sinking into the wood.