Specification Bolts

Specification Bolts & Nuts Manufacturers

ASME SA194 2H / 2HM / 4 / 7 / 7L / 7M / 8/ 8M / 8MA:

ASME SA194 (ASTM A 194) generally stands for all carbon steel, stainless steel alloys & materials that are suitable for almost all the high temperatures / high pressure application nuts. High resistance ASME SA194 2H nuts find their most common usage in the petrochemical industry. The standard shape is generally in accordance with the ANSI A18.2.2 TAB. 10 UNC Series Class 2B or 8 UN Series Class 2B or in accordance with the metric standard ASTM A194 M (ASME SA 194) EN ISO 4033.

A194 2H: Carbon Steel Heavy Hex Nuts; Quenched & Tempered

A194 2HM: Carbon Steel Heavy Hex Nuts; Quenched & Tempered

A194 4: Carbon-Molybdenum Heavy hex Nuts; Quenched & Tempered

ASME SA320 L7 / L43 / B8 / B8M

ASME SA320 specs bolting are widely used for low temperature application in Petrochemical Industry and related fields. The subject ASME and ASTM Standard covers the steel and stainless steel alloys suitable for fastening materials involving low working temperature. Besides, this includes specifications of fastening devices that are utilized in pressure vessels, valves, fittings and flanges. Briefed below is the basic summary of ASME SA320 / ASTM A320 along with their further standard specifications:

SA320 L7 Alloy steel, AISI 4140/4142; Quenched and tempered

SA320 L43 Alloy steel, AISI 4340; Quenched and tempered

ASME SA193 B8M/ SA320 B8M

At BBI, we produce stud bolts and screws in A193 B8M & A320 B8M. This happens to be a NI-Cr not tempered stainless steel (austenitic) that is hardened by means of cooling warping. Compared to the type 304, it is known to exhibit a higher corrosion resistance, especially with regards to the pitting that is caused by the chloride ions.

A193 B8M & A320 B8M is largely used in equipments such as heat exchangers, pressure vessels, parts of furnaces & in industries including chemical, photographic, pharmaceutical, food, textile, paper and orthopedics. Its corrosion resistance is outstanding in atmosphere as well as in a range of salts, food substances and organic acids. Compared to austenitic steels, it is much better.

INCOLOY® Alloy 925 UNS N09925

Austenitic steel with a nickel-iron-chromium base and additions of titanium, molybdenum, aluminum and copper, INCOLOY® 925 involves precipitation hardening. It offers excellent corrosion resistance combined with high mechanical strength. All these make INCOLOY® 925 superior and upper grade when compared to INCOLOY ® alloy 825.

In general, this alloy is characterized by exhibiting high resistance to corrosion, stress-corrosion cracking and crevice corrosion in a lot of aqueous environments that include those comprising of chlorides and sulphides.


At BBI, we manufacture stud bolts and nuts – ASTM A193 B8R NITRONIC 50 XM-19 Stainless Steel which offers a unique combination of strength and corrosion resistance. This austenitic stainless steel possesses high corrosion resistance when compared to the Types 316, 316L, 317 and 317L as well as almost twice the yield strength (recorded at room temperatures). Moreover, ASTM A193 B8R NITRONIC 50 XM-19 stainless steel exhibits excellent mechanical properties both at elevated & sub-zero temperatures. In addition, unlike many other austenitic stainless steels, ASTM A193 B8R NITRONIC 50 XM-19 doesn’t turn magnetic when cooled or cold worked to sub-zero temperatures. HS (High Strength) ASTM A193 B8R NITRONIC 50 XM-19 stainless steel tends to have yield strength of approximately three to four times of Type 316 stainless steel.

INCONEL® alloy 718 UNS N07718

Inconel™ 718 Material Property Data Sheet

At BBI, we are capable of supplying Stud Bolt & Nuts in INCONEL® alloy 718 UNS N07718.

ASME SA453 GR 660 A/B/C/D

BBI specializes in supplying stud bolts and nuts ASTM A453 GR 660, Alloy 286, 1.4980 materials. It happens to be a precipitation hardening steel that is heat resistant. It is highly recommended in terms of high mechanical resistance & corrosion resistance (up to 700°C). The product is suitable for use in jet engines, gears, turbines, paddles, spring washers, nuts, bolts, and other devices which demand high temperature resistance.

Corrosion resistance of ASTM A453 GR 660 – ASTM A286 GR 660 is too good – up to 700°C. Oxidation resistance is up to 800°C in the current “on-order” conditions & up to 980°C in intermittent “on-order” conditions.

Duplex ASTM A182 F55

BBI produces SUPERDUPLEX ASTM A182 F55, UNS 32760, EN 1.4501 screws, stud bolts and nuts; double-phase stainless steel, Cr-Ni-Mo-N pitting resistant & stressed corrosion resistant.

An austenitic & ferritic structural stainless steel, ASTM A182 F55 exhibits excellent mechanical and corrosion resistance. Moreover, it is appropriate to be used in parts, pumps and valves under pressure, conditions subject to corrosion & in case of centrifugal pumps when under heavy corrosive conditions.

ASTM A182 F55 is by far the best material among the austenitic Cr-Ni types perhaps even in the presence of chlorides. Its corrosion resistance shows the maximum result at a soluble status and hence we recommend not using it at a temperature exceeding 300°C.