M8 Thread Lags | McMaster-Carr

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17 Products

Steel Hex Head Wood Screws

Often used on posts and beams, the coarse threads on these screws dig in for a firm hold. The hex head's six contact points keep sockets in place to avoid slipping and stripping the drive. To tighten, use a wrench or six-point hex socket. Also known as lag bolts.

Drill a pilot hole slightly smaller than the screw to prevent splitting. Length is measured from under the head.

Zinc-Plated Steel—A common choice for areas with occasional exposure to moisture.

	Tapping Method	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel







	M8 × 3.6 mm

	25	5.5	Partially Threaded	Thread Forming	DIN 571	25	97498A135	00000


	30	5.5	Partially Threaded	Thread Forming	DIN 571	25	97498A136	0000
	35	5.5	Partially Threaded	Thread Forming	DIN 571	25	97498A137	0000
	40	5.5	Partially Threaded	Thread Forming	DIN 571	25	97498A138	00000
	45	5.5	Partially Threaded	Thread Forming	DIN 571	25	97498A139	00000
	50	5.5	Partially Threaded	Thread Forming	DIN 571	25	97498A141	00000
	55	5.5	Partially Threaded	Thread Forming	DIN 571	25	97498A142	00000
	60	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A143	0000
	70	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A144	0000
	80	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A145	0000
	90	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A146	0000


	100	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A147	0000
	120	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A148	00000
	130	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A149	00000
	140	5.5	Partially Threaded	Thread Forming	DIN 571	10	97498A151	00000
	160	5.5	Partially Threaded	Thread Forming	DIN 571	5	97498A152	0000

Thread-Mount Studs for Wood

Also known as hanger bolts, use these studs to hang, mount, and fasten parts to wood structures. Install them with a stud driver, or create wrench flats by threading two nuts onto the stud and jamming them together.

316 Stainless Steel—Superior to 18-8 stainless steel, these studs won't degrade when exposed to harsh weather, salt water, and most chemicals.

	(A)		(B)
	Screw Size	Thread Lg., mm	Thread Size	Thread Lg., mm	Lg., mm	Tensile Strength	Hardness	Pkg. Qty.		Pkg.
316 Stainless Steel



		M8	57	M8 × 1.25 mm	40	100	Not Rated	Not Rated	1	98828A300	00000