Grade
2
This grade is from the SAE scale and made of low carbon steel. This classification is low on the grade scale.
2H
This is a high pressure and temperature grade nut made of medium carbon steel that has been quenched and tempered. This grade meets ASTM specification A 194. These nuts are also used in flanges and fittings as well as in heavy construction of buildings and bridges.
5
This grade is from the SAE scale. Made of medium to low carbon steel, it is of medium strength on the grade scale.
6/6
This is a specific designation of a polyamide or nylon plastic. This lightweight material doesn't have corrosion problems, is non-magnetic, non-corrosive, non-toxic, non-flammable and non-conductive. It is much weaker than the SAE standard grade 2, yet great in low strength applications where weight is at a premium.
8
This grade is part of the SAE classification; it is the minimum standard of the automotive and structural industries, plus it is used in high-temperature applications. Grade 8 is near the high end of the grade scale, although there are higher grades and strengths for more specialized fasteners.
9
At the top of the scale, this grade offers the most strength in a joint. There are no industry standards for this grade, however most have tensile strengths around 180,000 psi. This grade is used in high strength applications.
18-8
A general designation for the most common and popular stainless steel, (300 Series) referring to the 18% chromium and 8% nickel. It's strength has a range from the middle to low end of the grade scale. All 300 series stainless steel share the ratio of chromium to nickel with varying other elements improving different properties. It has higher corrosion resistance than the 400 series stainless steels and it is non-magnetic.
316
The second most common stainless steel grade, this material is stronger than grade 2, slightly weaker than grade 5,or generally as strong as medium to low carbon steel. It is on the low middle end of the grade scale. It is used in more severe corrosive environments than 304 stainless steel, as such it is used in more industrial settings, like process chemicals, textiles, bleaches, salt water and rubber. It is also used in surgical implants. The DIN/ISO denotation for a very similar grade is A4-70.
6061-T6
The least expensive and most popular aluminum alloy, 6061 has good mechanical properties, good welding properties, and corrosion resistance plus it is the most versatile heat-treated aluminum. The T6 temper designation means it is the strongest of the 6061 aluminum alloys with a tensile strength around 40,000 psi.
A
This grade is used in low strength applications. This grade meets ASTM specifications for A563 and is typically used with ASTM Grade A and B bolts or SAE grade 1 and 2 bolts.
A2
A type of the most common stainless steel grade. It is comparable in strength to grade 2 materials, yet slightly weaker and easy to weld. This grade is always metric. The ASTM denotation for very similar grade is 304. The corrosion resistance and ease of fabrication are why this grade is used in food industry machines, appliances, architectural trim and aquatic fasteners.
A4
The second most common stainless steel grade, this material is stronger than grade 2 and generally as strong as medium to low carbon steel. It is on the low middle end of the grade scale. This grade is always metric. The ASTM denotation for a very similar grade is 316.
C
This nut grade denotation is for nuts that are used in heavy construction. They are marked with three curved lines around the central hole. This grade meets ASTM A563 specifications and is commonly used with ASTM A325 and ASTM A354 bolts.
Class 10
This is a metric nut grading similar to the SAE grade 8 classification, which is used in conjunction with Class 10.9 bolts. This strength of nut is used in automotive, and structural industries, as well as in high temp applications. Its strength is near the high end of the grade scale, although there are higher grades and strengths for more specialized fasteners.
Class 8
This is a metric nut grading similar to the SAE grade 5 classification, which is used in conjunction with Class 8.8 bolts. This is a medium strength nut.
F
This nut grade is for use with grade 5 bolts and usually denotes hex flange nuts.
G
This nut grade is for use with grade 8 bolts and usually denote hex flange nuts.
