Good high temperature oxidation resistance to 2000°F

• 

  High temperature stability for moderate strength applications
• Good oxidation and carburization resistant to 2000°F
• Resistance to moderate sulfidation and nitriding
• Economic alternative to high temperature nickel alloys
• 310SS chemistry & specifications
• Features & benefits of 310SS 12-point screws
• Datasheet for 310 stainless steel

Designed for high temperature applications, 310 stainless steel 12 point screws provide high temperature oxidation resistance to 2000°F under mild cyclic conditions. An economic alternative to nickel alloys like alloy 330 or Inconel, 310 screws provide slightly less strength and temperature resistance – but at a significantly lower price point.  Alloy 310 12 points can be used in moderately caburizing, moderately oxidizing, nitriding, cementing and thermal cycling applications when not used at the maximum service temperature. 310SS screws also have good resistance to sulfidation and other forms of hot corrosion.  Although primarily known for its high temperature properties, 310 12 point screws also provide excellent performance at cryogenic temperatures, with toughness down to -450˚F. Though 310 is ideal for high temperature use, it should not be exposed to the severe thermal shock of repeated liquid quenching or where aqueous corrosive contaminants are present.

Benefits

• High temperature resistance.
• Excellent resistance to oxidation under mildly cyclic conditions.
• Good resistance to sulfidation and atmospheres where sulfur dioxide gas is encountered at elevated temperatures.
• Good resistance to thermal fatigue.
• Excellent toughness to cryogenic temperatures of -450°F.
• Low magnetic permeability.
• Good ductility and weldability.

Applications

• Thermal processing and high temperature furnaces rely on 310 12-point screws for their high temperature and oxidation resistance in minor cyclic conditions.
• 310SS 12 points are commonly used in the petrochemical industry for their ability to provide resistance to moderately carburizing atmospheres.
• The high temperature properties of 310 screws make them ideal for ore processing, steel plants, power generation, and sintering.
• Cryogenic structures often use 310SS 12 point screws for their strength at -450°F and low magnetic permeability.

Resources: Flange Dimensions, Flange Bolting Chart

Alloy 310 Screw Types: 12 Point Screws, Button Head Cap Screws, Flat Head Screws, Hex Head Cap Screws, Pan Head Screws, Set Screws, Socket Head Cap Screws, Tamper Resistant Security Screws, Torx Screws, Vented Screws

310 Stainless Steel Chemistry & Specifications

310SS Specifications: AMS 5521, AMS 5651, ASME SA 240, ASME SA 312, ASME SA 479, ASTM A 240, ASTM A 276, ASTM A 276 Condition A, ASTM A 276 Condition S, ASTM A 312, ASTM A 479, EN 10095, UNS S31008, UNS S31009, Werkstoff 1.4845

310SS 12-Point Screw Features & Benefits

The driver of a 310SS 12-point screw uses two overlapped hexagon shapes, creating 12-points and a flanged underside. These are also referred to as ferry cap screws or 12 point flange screws. The advantages of this head style include:

• Higher torque capability compared to a socket head cap screw
• Lack of recess to trap fluid or debris.
• As the heads are generally smaller than a hex, alloy 310 12-point screws are often used situations where installation space is tight and saving weight is critical.

The overall disadvantage is the extra cost involved in forming the heads.

The Controversy of 6 vs. 12 point Bolts

There is much debate over which bolt is better. Some say that the more points a nut or bolt has – such as a 12-point bolt - the less chance you have to round it off. And that the additional contact points of a 12 point screw give you more surface to apply load. While the jury is out as to the accuracy of this, it’s the application that should dictate whether the benefits of a 12 point screw out weight the additional costs of making them.