We are a little late to this discussion but I wrote a blog/case study on the subject here a while ago:
Machined Stainless Steel Safety Razor Grades and Other Metals
Quote:I have noticed that most of the boutique razors made in the USA and Europe use 303 or 304 stainless steel rather than 316L. There are certainly exceptions, but Blackland, Timeless, Above the Tie, Karve, Tatara, and others use the softer and less durable 303 or 304 SS rather than marine grade 316L. Yaqi, Feather, Paradigm, RazoRock, Wolfman, and others are the exceptions who use 316L. My question is why, or rather why not? There must be a reason besides cost. After all if RazoRock can produce good quality razors out of 316L for $70 and Yaqi for even less, then why not Blackland Razors, Timeless, tatararazors, and Karve? There must be a reason, and I'd like to know why.
An "MR" rating or "Machinability Rating" is a way to compare how easier a material is to machine vs another material. Stainless steel grade 303 (MR rating of .65) and 304(MR rating of .41) are much easier to machine compared to 316(MR rating of .35)...303 is the cheapest to machine by far! These grades of stainless steel are also far less corrosion resistant than 316L. We considered using 303 when we first started and while it was significantly more profitable, we didn't like the material at all for the following reasons:
- Sulfur is added to the material which makes it a far less expensive grade of stainless to machine than other stainless grades. The sulfur creates voids in the material which allows you to machine the stainless steel quicker, cooler, and without coolant(smaller chips). This reduces its corrosion resistance.
- Ease of machining makes it much cheaper to machine, however it comes at a significant expense to its corrosion resistance. Shaving companies who use this material recommend you remove the blade after use, so as to not get rust or what they call tea stains on your shaver. Water will collect in the small tight unaccessable areas like the threads and rust over time.
- 303 is not recommended for earrings, watches, rings, nor is it considered food grade stainless(by the FDA)...in some countries, it is banned for these applications.
- In a humid environment like a bathroom with tap water which has salt, (especially if you have have a water softener) a marine grade stainless steel is a better choice. We assume our customers will neglect their razor....leave the blade in!
- 316L will finish to a higher, brighter polish than other stainless due to the addition of molybdenum.
I am not sure I answered
draebeard question regarding why 303 but this is why we chose 316L.
With regards to 304, we do use 304 in our stainless Damascus Cx razors, I wrote a blog about damascus(writing helps me focus):
Damascus Steel Safety Razor and its origins
The history of Damascus steel as it relates to sword making is an interesting one and seems relavent to this discussion as some consider it the earliest form of material science. Similar to the OP's question.
In the photo below you can see both metals after we etch the forged metal in warm acid (a sketchy experience!). The valleys on the surface are 304, where the acid corroded the metal, the peaks in the surface are 316L. While acid is not a part of the shaving experience, it does show the relative corrosion resistance of the 2 metals in relation to each other, 316L is very durable:
With regards to 904L stainless:
Quote:Surely 904L steel is overkill then.
Stephanos provided some good insight into this steel alloy some time ago.
I feel compelled to answer this as we are the only manufacturer to have ever used this material in a safety razor. Rolex switched to this grade of stainless steel in the '80's because of corrosion around their threads....it doesn't get better in terms of a stainless material! Total overkill...Rolex gets the same wrap on its blogs
I appreciate the opportunity to respond...stay well!
A small company trying to make a great razor...