Custom Material & Alloy Selection Services
Triad Bellows offers custom material and alloy selection to meet the unique demands of your application, ensuring each metal bellows assembly is optimized for performance, durability, and compatibility. Whether you’re dealing with high temperatures, corrosive media, or extreme pressure conditions, Triad’s engineering team will help select the ideal material—ranging from standard T-321 and T-316 stainless steel to high-performance alloys such as Inconel®, Hastelloy®, Monel®, or Alloy X. This flexibility allows fabricators, OEMs, and end-users to tailor each bellows to specific chemical, thermal, or mechanical environments. With every bellows built to EJMA 10th Edition standards, Triad ensures your custom alloy selection is integrated without compromise—delivering long cycle life, superior weld integrity, and unmatched reliability in the field. Whether you require enhanced corrosion resistance, higher fatigue strength, or specialized metallurgical properties, Triad Bellows provides expert guidance and fast, precision fabrication to match your material needs.
Alloys Used in Bellows and Light Accessories Forming
Listed below are some of the materials we use for creating both our standard and custom metal bellows and expansion joints. Depending on the intended function of the product, we use different alloys that can resist different temperatures, avoid corrosion cracking, and more. Both our stainless steel bellows and expansion joints are crafted from superior materials to give you the quality you deserve. If you have any questions or concerns about our manufacturing process or the materials used in our metal bellows, Triad Bellows’ experts are here to help. Please give us a call today.
ASTM A240 T-321
Heat resistant alloy for bellows limited to 1200º F
Titanium stabilized grade of 300 series stainless steel
Optimum resistance to inter-granular corrosion and stress corrosion cracking
ASTM A240 T-304/304L
Heat resistant alloy for bellows limited to 1200º F
Titanium stabilized grade of 300 series stainless steel
Optimum resistance to inter-granular corrosion and stress corrosion cracking
ASTM A240 T-316/316L
Applied to temperatures up to 1000ºF
Offered in dual certification
Provides excellent corrosion resistance
Alloy stabilized with molybdenum
ASTM A240 T-310
Temperature range up to 1500ºF
Austenitic heat resistance alloy
Excellent resistance to oxidation
Limited availability in bellows material thickness
ASTM B-536 ALLOY 330
Recommended up to 1500ºF
High nickel alloy
Combination of strength and resistance to carburization
Resistant to oxidation and thermal shock
ASTM B-168 ALLOY 600
Inconel 600
Operates at elevated temperatures up to 1200ºF
High nickel alloy with great carburization and oxidation resistance
Resistant to chlorides, dry and gaseous at elevated temperatures
Not recommended for use in extreme heat where sulfur is present
ASTM B-443 ALLOY 625
Inconel 625
Temperature resistant up to 1200ºF
High nickel alloy with outstanding strength
Aqueous corrosion resistance due to content of molybdenum and columbium
ASTM B-435 ALLOY X
Hastelloy X
Recommended for temperatures up to 1500ºF
High nickel alloy grade with excellent strength
Oxidation resistant
ASTM B-575 ALLOY C-276
Hastelloy C-276
Temperature limited to 1200ºF
High nickel molybdenum and chromium alloy with traces of tungsten
Excellent resistance to pitting and stress corrosion cracking
Used for heat exchangers, ducting and marine applications
Alloys Used for Hardware with Expansion Joint Manufacturing
ASTM A-36
Carbon based steel plate used for plate flanges, tie rod ears, and gussets in temperatures up to 750ºF
ASTM A-516 GR.70
Stronger alloy steel plate with better properties than A-36 plate
flanges and hardware up to 1000ºF
ASTM A-240
T-304, T-316, T-321
Stainless steel plate used for special plate flanges, gimbal hardware, etc. up to 1000ºF
ASTM A-53-E GR.B
Carbon based steel pipe, welded and spot radiograph checked on the seam weld rated to 750ºF
ASTM A106 GR.B
Higher grade carbon steel pipe, seamless provides weld efficiency of 100% radiographed seam rated to 750ºF
ASTM A-105
Forged steel RFSO flanges, couplings, temperature and pressure rating varies
ASTM A-234 GR WPB
Pipe elbows, concentric reducers, and other non-forged carbon steel fittings
ASTM A182 F GRADES
304/304L, 316/316L
Basic stainless steel forging, covers RFSO flanges couplings, temperature and pressure rating varies
ASTM A-312 GRADES
304/304L, 316/316L
Covers stainless steel pipes and pipe based products with temperatures up to 1000ºF
ASTM A-193 GR B7
Alloy steel threaded rod and bolts used in conjunction with restrained expansion joints
ASTM A-194 GR 2H
Alloy steel heavy duty hex nut paired with ASTM A-193 GR B7 threaded rod and bolts
ASTM A-193 GR B8
Certified stainless steel threaded rod used in conjunction with restrained expansion joints
ASTM A-194 GR 8
Certified stainless steel hex nuts paired with ASTM A-193 GR B8 threaded rod and bolts
