Grade 15-5 PH* investment cast body and hasp for very high strength and corrosion resistance
Heavy duty 316 stainless plunger springs and precision components ensure dependable service
Body and hasp profiles are designed for easy clearance of lines and fittings when released
All stainless steel construction for excellent corrosion resistance
Split ring on plunger pin is spot welded for extra security
High strength to weight ratio


Heavy on the technical side...

About 17-4 PH and 15-5 PH Stainless Steels...

Precipitation-Hardening (PH) Stainless Steels are martensitic alloys which contain approximately 17% chromium and 4% nickel. This makes them as corrosion resistant as the more common 300 series austenitic grades of stainless steel (304, 316, 316L, etc.). However, heat treatment strengthens PH steels to levels higher than 316 or even 316L alloys.

There are two general groups of PH grade stainless steels; martensitic and semi-austenitic. The martensitic group includes the very similar 17-4 PH and 15-5 PH alloys. They develop their high strength and hardness through heat treatment. The martensitic PH steels are used in aerospace, chemical and petrochemical, and food processing applications.15-5 PH stainless steel offers high strength and hardness with excellent corrosion resistance. SS 15-5 can be age-hardened by a low temperature treatment. 15-5 PH stainless steel offers good corrosion resistance, and high strength therefore has been used for aerospace applications.17-4 PH stainless steel features good corrosion resistance, hardness, toughness and strength. 17-4 PH Stainless Steel is a very widely used precipitation hardened alloy with a toughness especially suited for industrial applications. The semi-austenitic grades are 17-7 PH and PH 15-7 Mo. They are austenitic in the annealed state, but martensitic in the hardened condition. http://www.aksteel.com/pdf/markets_products/stainless/stainless_steel_comparator.pdfhttp://www.californiametal.com/stainless.htmBy comparison
Type 302 same corrosion resistance as 304, with slightly higher strength due to additional carbon.
Type 304 the most common grade; the classic 18/8 (18% chromium, 8% nickel) stainless steel. Outside of the US it is commonly known as "A2 stainless steel", in accordance with ISO 3506 (not to be confused with A2 tool steel).
Type 316 the second most common grade (after 304); for food and surgical stainless steel uses; alloy addition of molybdenum prevents specific forms of corrosion. It is also known as marine grade stainless steel due to its increased resistance to chloride corrosion compared to type 304. 316 is often used for building nuclear reprocessing plants.
Type 316L is an extra low carbon grade of 316, generally used in stainless steel watches and marine applications, as well exclusively in the fabrication of reactor pressure vessels for boiling water reactors, due to its high resistance to corrosion. Also referred to as "A4" in accordance with ISO 3506.[6]