Metallic gasket can refer to an all-metal or semi-metallic gasket. Semi-Metallic gaskets are made by combining soft materials such as fillers or facings, with a metallic base or winding. The metal component provides strength and, depending on the configuration, elasticity while the soft materials conform to the flange surface and create seal. A common type of Semi metallic gasket used in industry is the Spiral Wound gasket. Purely metallic gaskets are fabricated from a single metal or a combination of metallic materials in a variety of shapes and sizes. These metallic gaskets are suitable for high temperature and pressure applications. Higher loads are required to seat metallic gaskets. Types include flat, grooved, round cross-section solid metal, lens rings, Ring Type Joints (RTJ’s) and welded gaskets.
Common Metallic Gasket Materials
The following is a listing of the more common metals used in manufacturing both semi- metallic and metallic gaskets. It is not intended to be a list of all available materials, only the typical materials. For a more complete listing, contact your gasket supplier or manufacturer to discuss all the materials which they may have available. Refer to EN 10027-1 and EN 10027-2 Designations Systems for Steel Part 1: Steel Names and Part 2: Steel Numbers and The Unified Numbering System (UNS) for Metals and Alloys for complete list of metal standards.
The most commonly used material for manufacturing double jacketed gaskets. It has poor resistance to corrosion and should be used with caution when in contact with water or diluted acids.
Type 304 Stainless Steel (1.4362)
This material is widely used in the manufacture of industrial gasketing, due to its low cost and excellent resistance to corrosion.
Type 316 (1.4401) /316L (1.4404) Stainless Steel
This material generally offers a higher resistance to corrosion than type 304SS.
Type 321 Stainless Steel (1.4541)
This alloy is similar to 304SS but titanium is added. It is widely used in high temperature corrosive applications.
Type 347 Stainless Steel (1.4550)
This alloy is similar to 304SS but columbium and titanium are added. It has good performance in high temperature corrosive applications.
Type 410 Stainless Steel (1.4006)
This stainless steel is a heat treatable 12% chromium steel, which combines good general corrosion resistance with high strength.
Total Sealing Integrity
As Total Sealing Integrity and Asset Management specialists, we create and promote best bolting practices for our customers through consultation and safety training. We emphasize and develop practices toward achieving bolted joint reliability, gasket selection criteria specific to our customers' unique applications and regularly manage and update our customers’ equipment database. We provide site surveys, inspections, and audits of our customer’s equipment through our technical services group and offer virtual, on-site or in-house training programs. Contact your local A.R. Thomson Group or view our Total Sealing Integrity brochure for more details.