There’s a fair chance that 95% of the hardware in your kitchen is made of stainless steel, but how much do you really know about the catering industry’s most ubiquitous material? If you struggle to tell the difference between your 304 austenitic and your 430 ferritic, you could be specifying the wrong equipment for the job, writes Ian Canavan of YCE Catering Equipment and Busychef.
Have you ever noticed that some stainless steel is more durable than others? Ever wondered why some is magnetic and some is not? It turns out that stainless steel is a broader concept than many realise, referring simply to a group of hybrid metals (‘alloys’ if you like). Why should you, a foodservice business buyer, need to know about stainless steel though?
Being properly aware of what you’re investing your money into is important. You don’t want to buy a product which is insufficient for your needs, nor do you want to spend money on a piece of equipment which provides more protection than you really need.
So, let’s talk stainless steel. Stainless steel alloys are made by mixing iron with at least 10.5% chromium, as well as other metals and materials like carbon. The different ‘recipes’ for stainless steel result in different types, impacting price, strength and corrosion resistance.
You may have noticed we label benches ‘430 grade’. That description tells you something about its composition. It’s part of a larger group called ‘ferritic’ stainless steel. Another group common in foodservice is ‘austenitic.’ Most commercial sinks are made from a type of austenitic steel tagged ‘304 Series.’
All of this can get rather confusing, but YCE and Busychef have been making stainless steel benches, sinks and shelves for more than 35 years, so let me break it up a bit for you and explain further.
The most common type of steel used today, austenitic steel accounts for 70% of steel production. Because of the materials used in this alloy, it’s particularly resistant to corrosion.
304 Austenitic Stainless Steel
Known for being the most common type of stainless steel used, 304 is practical and hardy. It’s resistant to food products, sterilising solutions and most organic materials. Because of its superior rust protection, it’s used in sink bowls and other surfaces which are most likely to come in contact with corrosive substances. Unfortunately, due to the high cost of nickel and how difficult it is to work with austenitic steel, this is more expensive than many other stainless steel options.
201 Austenitic Stainless Steel
You could consider 201 the kid brother of 304, since they share a similar chemical composition. It’s still food safe, but doesn’t hold up to corrosion quite as well, so it’s not going to withstand chemicals like bleach. Because of this, it tends to be less expensive. You’ll often find it in the form of handwashing sinks, but we won’t use it for fabrication.
The main way ferritic steel differs from austenitic is that is contains nickel and is also magnetic. Want to find out if your stainless steel is austenitic or ferritic? Grab yourself a magnet. If it sticks, it’s ferritic. It’s known for being both corrosion resistant and holding up against stress.
430 Ferritic Stainless Steel
For environments with less chemical use, 430 is a great option as it’s made with chromium. 430 is used most often for ovens, refrigerators and economic cost sinks or tables. While it may be cheaper, if properly taken care of it can last you a long time and will end up being a wise investment. We tend to use 430 for items such as undershelves and wall shelves.
316 Ferritic Stainless Steel
316 isn’t something you’ll find very often in the restaurant world, though it’s been known to pop up occasionally, like in food trolleys meant for hospitals or food processing equipment. It’s extremely corrosion resistant because it has larger quantities of nickel, and as such it is mainly used in the medical world. Because of the amount of nickel it contains, it’s difficult to fabricate, and so is quite expensive.
Counter-intuitively, the lower the gauge number, the thicker the steel. Take note that while the steel may have a lower gauge, and therefore be thicker, the type of steel still matters. Gauge is just the density, not the quality.
Also known as the economy gauge, for a lower cost you get a respectable piece of stainless steel. It tends to work best for things like wall shelves and undershelves. (1.24mm)
This is where you get the most bang for your buck. It’s a quality thickness which will serve many uses, but won’t break your budget. You’ll find plenty of well-built sinks and prep tables which use 16-gauge. (1.65mm)
The perfect gauge for butchers. You can hammer and hack things on this gauge all day long without bowing the stainless steel. It’s also going to look smooth and sleek over a longer period of time. (2.11mm)
Who discovered stainless steel?
The story behind the discovery of stainless steel is riddled with complexity, according to the British Stainless Steel Association. However, it notes that there is a widely held view that stainless steel was discovered in 1913 by Sheffield metallurgist Harry Brearley. He was experimenting with different types of steel for weapons and noticed that a 13% chromium steel had not corroded after several months.
Ian Canavan is website manager at YCE Catering Equipment and www.busychef.co.uk, one of the UK’s top independent suppliers and installers of commercial foodservice equipment.