HIGH STRENGTH STAINLESS STEEL FASTENERS
Stainless steels are well known for their excellent corrosion resistance. The austenitic 300 and A2 series are covered by ASTM Specification F593/594 and ISO 3506. Both series are essentially 18-8 (18% chromium and 8% nickel) materials, with compositions very close to the nominal composition of Type 304/A2. If an application calls for a material with better corrosion resistant properties, type 316/A4 are the next logical choice. Type 316/A4 stainless steel is a higher alloyed material containing a minimum of 2% molybdenum, which provides better pitting and crevice corrosion-resistant properties, especially in environments containing chlorides. For high temperature or high pressure services and other special purpose applications, the B8 and B8M classes of stainless steel alloys are specified in ASTM A193/193M for bolts and ASTM A194/194M for corresponding nuts.
Higher corrosion resistance is achieved by a special steel alloy that has reduced carbon and increased molybdenum of minimum 2,5%. It is called High Molybdenum or just HiMo/HiMo+.
In modern construction there is not only a demand for high corrosion resistance, but also a demand for fasteners with increasing properties of strength, like SAE grade 5 or metric class 8.8/8 (according ISO 898). In the past poor corrosion resistance in aggressive environments has always been a big disadvantage for these types of steels.
But now there is TS HiMo88® – another product for maximum performance and high strength stainless steel grade for Fasteners.
With the perfect combination of superior corrosion resistance and high strength like 8.8 (higher than A4-80) TS HiMo88® is the perfect choice for all applications related to water, aggressive liquids, vibration, high pressure as well as applications in marine environments.
Steel Comparison Data
|Grade||Standard||C %||Cr %||Ni %||Mo %||Cu %|
|A4-70||ISO 3506||0,08||16,0 – 18.5||10,0 – 15,0||2,0 – 3,0||4,0|
|A4-80||ISO 3506||0,08||16,0 – 18.5||10,0 – 15,0||2,0 – 3,0||4,0|
|316/316L||ASTM/AISI/UNS||0,08/0,03||16,0 – 18,0||10,0 – 14,0||2,0 – 3,0||n/a|
|A193-B8M||ASTM A193/A194||0,08||16,0 – 18,0||10,0 – 14,0||2,0 – 3,0||n/a|
|Bumax88®||Bufab trademark||0,03||16,5 – 18,0||11,0 – 14,0||2,5 – 3,0||0,6|
|HiMo88®||TS trademark||0,03||17,0 – 18,0||12,5 – 14,0||2,5 – 3,0||0,4|
Mechanical properties and PRE-values
|MPa min||MPa min||min|
|SAE Gr 5/8.8||ISO 898||800||640||0,00|
|B8M2 (<M20)||ASTM A193/A194||760||655||22,60|
Product Range TS HiMo88®
- ISO 4017 Screws: M 3 to M 24
- ISO 4014 Bolts: M 3 to M 24
- ISO 4032 Nuts: M 3 to M 24
- ISO 4762 Socket cap screws: M 3 to M 24
- ISO 7089 Washers HV200: 3 to 25
- ISO 10642 Countersunk screws M 3 to M 20
- DIN 938/939 Engineering studs: M 3 to M 30
- DIN 975/976 Threaded bars and studbolts: M 6 to M 30
- Raw material up to 30 mm diameter available to manufacture numerous parts according to various standards and drawings on request
Benefits of HiMo fasteners and the TS HiMo88®
- Superior resistance to corrosion
- TS HiMo88® can replace Grade 5 or class 8.8/8
- Higher strength in fasteners tends to result in lower weights
- For low and high temperature applications from -200 to +400 °C
- Non-magnetic (permeability <1.01)
- Full traceability and certificates EN 10204/3.1 available
- Triple certifications and marking available (e.g. HiMo88 A4L-316L80)
- Approval for Pressure Vessel applications according PED 97/23/EC optional
TS HiMo88® a secure connection for many applications