Although all Stainless Steel share the basic characteristics of resisting corrosion, there are many different families of stainless steel and they all have strengths and weakness. It is a constant battle to strike a balanced compromise between hardness and corrosion resistance.
At Steritool we work hard to select the appropriate alloy for the intended use of a tool. Of course, we understand customers have unique needs and we pride ourselves in being able to make most tool from any alloy that your application may require.
The two extremes we see in our day to day lives are the 300 & 400 series Stainless Steel. 300 series is often used in common household appliances. It has the highest corrosion resistance, but is the softest Stainless alloy. On the opposite end of the scale is 400 series (exclude 465) Stainless Steel which is often used in bearings that allow various mechanical components in our daily lives to operate smoothly. 400 series Stainless is very hard but lacks the corrosion resistance of other Stainless alloys.
We use both 300 & 400 series stainless steel and the most common alloys that fall in-between those two extremes.
Below is a simple breakdown of the common Stainless Steel alloys we use and their characteristics:
SS ALLOY |
CHARACTERISTICS |
HARDNESS |
YIELD/TENSILE |
USE |
304 |
Non-Magnetic (4 Tesla), high level of corrosion resistance, resistant to many chemicals, soft, can not be hardened. |
70 HRB (25HRC) |
31 / 73 KSI |
Balls, Springs, Screws, Stand offs, Rivets, etc. |
316 / 316L |
Non-Magnetic (4 Tesla), very high level of corossion resistance, resistant to most chemicals, soft, can not be hardened. Commonly used in chemical storage tanks and washdown areas. |
80 HRB (28 HRC) |
30 / 75 KSI |
Handles & Intermediate Shafts, Square Drive Collars, Power Bit Collars, Bit Collars, Low Stress/Torque Components, Balls, Springs, Screws, Rivets, etc. |
BioDur 108 |
Non-Magnetic (10 Tesla), extreme resistance to magnetism, similar corrosion resistance to 316L, can not be hardened, implant quality alloy, limited availability. |
43 HRC |
199 / 254 KSI |
Custom Non-Magnetic Tools made from Round Stock. Limited availability. |
Inconel 718 |
Non-Magnetic (5 Tesla), highly resistant to high temperatures/pressure (used for exotic exhaust/jet engines/pressure tanks), hardened by heat treating, high level of corrosion resistance. |
45 HRC |
170 / 200 KSI |
Non-Magnetic Tools made from Round Stock (hex keys, screwdrivers, etc) and Flat Stock (wrenches, etc.). |
17-4PH |
Magnetic, high level of corrosion resistance, resistant to most chemicals, hardened by heat treating, available in wide range of raw material. |
46 HRC |
170 / 190 KSI |
Sockets, Nut Drivers, Hammers, Wrenches, various components used in assemblies, etc. |
465 |
Magnetic, strong, high level of corrosion resistance, resistant to most chemicals, hardened by heat treating, good resistance to torsional loads, available in wide range of round stock. |
50 HRC |
239 / 254 KSI |
All Hex Key & Screwdriver products and other tools that require torsional strength. |
420 |
Magnetic, high strength, hardened by vacuum heat treating, brittle, medium corrosion resistance, requires prompt washdown/dry process (can be TiN coated to increase corrosion resistance) |
52 HRC |
200 / 236 KSI |
Chisels, Hole Punches, Scissors, Pliers, some Wrenches, etc. |