Nuts: Materials, Finishes, and Applications

Materials Offered:

We offer nuts manufactured from a variety of materials including: low carbon steel (mild steel), middle carbon steel, alloy steel, stainless steel, brass, and aluminum alloy.

Surface Treatments for Enhanced Performance:

To meet diverse requirements for corrosion resistance or strength, nuts can undergo further treatment processes such as: heating, black oxide, zinc coating, hot-dip galvanizing, black zinc coating, brass coating, nickel and chrome plating, and dacromet. Please indicate these requirements with your inquiry.

Stocked Nut Types:

We maintain a comprehensive stock of various nut types, including commonly used standards like DIN934, DIN6923, DIN1587, DIN928, DIN929, and cage nuts.

Material Chemical Composition (Stainless Steel Grades):

GRADE	CHEMICAL COMPOSITION (% MAXIMA UNLESS STATED)									NOTES	ALTERNATIVE NAMES
	C	Si	Mn	P	S	Cr	Mo	Ni	Cu
A1	0.12	1	6.5	0.2	0.15/0.35	16-19	0.7	5-10	1.75-2.25	2 3 4	303S31, 303S42, 1.4305
A2	0.1	1	2	0.05	0.03	15-20		8-19	4	6 7	304, 394S17 (BS3111), 1.4301, 1.4567
A3	0.08	1	2	0.045	0.03	17-19		9-12	1	8	321, 1.4541, 347, 1.4550
A4	0.08	1	2	0.045	0.03	16-18.5	2-3	10-15	4	7 9	316, 1.4401, 1.4578
A5	0.08	1	2	0.045	0.03	16-18.5	2-3	10.5-14	1	8 9	316Ti, 1.4571, 316Cb, 1.4580
C1	0.09-0.15	1	1	0.05	0.03	11.5-14	–	1	–	9	410, 1.4006
C3	0.17-0.25	1	1	0.04	0.03	16-18	–	1.5-2.5	–		431, 1.4057
C4	0.08-0.15	1	1.5	0.06	0.15-0.35	12-14	0.8	1		2 9	416, 1.4005
F1	0.12	1	1	0.04	0.03	15-18		10	1	11 12	430, 1.4016, 430Ti, 1.4520, 430Cb, 1.4511

Application:

In applications where vibration or rotation may work a nut loose, various locking mechanisms may be employed: lock washers, jam nuts, specialist adhesive thread-locking fluid such as Loctite, safety pins (split pins) or lockwire in conjunction with castellated nuts, nylon inserts (Nyloc nut), or slightly oval-shaped threads.

The most common shape for nuts is hexagonal, for similar reasons as the bolt head – 6 sides offer a good granularity of angles for a tool to approach from (beneficial in tight spots), while providing sufficient grip. More (and smaller) corners would be vulnerable to being rounded off. It takes only 1/6th of a rotation to obtain the next side of the hexagon and grip is optimal. However, polygons with more than 6 sides do not provide the requisite grip, and polygons with fewer than 6 sides take more time to achieve a complete rotation. Other specialized shapes exist for certain needs, such as wingnuts for finger adjustment and captive nuts (e.g., cage nuts) for inaccessible areas.

A wide variety of nuts exists, from household hardware versions to specialized industry-specific designs that are engineered to meet various technical standards. Fasteners used in automotive, engineering, and industrial applications usually need to be tightened to a specific torque setting, using a torque wrench. Nuts are graded with strength ratings compatible with their respective bolts; for example, an ISO property class 10 nut will be able to support the bolt proof strength load of an ISO property class 10.9 bolt without stripping. Likewise, an SAE class 5 nut can support the proof load of an SAE class 5 bolt, and so on.