304 vs 316 Stainless Steel for Sanitary Fixtures: How to Specify Grade and Finish

"Stainless steel basin" appears on countless door and fixture schedules. But stainless steel comes in different grades and finishes, and the choice affects dura­bil­i­ty, ap­pear­ance and cost. A little extra detail in the spec­i­fi­ca­tion makes sure the right product is installed. Here's a practical guide based on the options available across the SMC Stainless range.

Why "stainless steel" isn't a spec­i­fi­ca­tion

Stainless steels are a family of alloys. They resist corrosion because chromium forms a thin pro­tec­tive layer on the surface, and different grades add other elements to improve per­for­mance in par­tic­u­lar en­vi­ron­ments. If a spec­i­fi­ca­tion just says "stainless steel", the grade is left to chance, and so is how well the product handles its en­vi­ron­ment.

Grade 304

Grade 304 is the most widely used stainless steel and the general-purpose choice for most indoor com­mer­cial ap­pli­ca­tions. It suits:

• Indoor washrooms and amenities
• Schools and offices
• Most health­care areas
• General com­mer­cial kitchens and food areas

Most SMC products are available in grade 304. The AT5-SFWVCR floor sump, for example, is made from grade 304 as standard (details).

Grade 316 (marine grade)

Grade 316 adds molyb­de­num, which improves re­sis­tance to chlorides such as salt and some chemicals. It suits:

• Coastal and marine en­vi­ron­ments, such as beachside parks and fore­shores
• Swimming pools and aquatic centres
• Lab­o­ra­to­ries and some clinical areas
• Areas cleaned with harsher chemicals

The SMC LS1 lab sink is con­struct­ed from grade 316 (details). Products such as the DFTB twin-bowl drinking fountain are available in marine grade 316 for coastal sites (details).

Choosing between them

Con­sid­er­a­tion	Grade 304	Grade 316
Typical en­vi­ron­ment	Indoor, general com­mer­cial	Coastal, pools, labs, harsh cleaning
Chloride re­sis­tance	Good	Better
Cost	Lower	Higher

If you're unsure, describe the en­vi­ron­ment to our team, including distance from the coast, cleaning chemicals and exposure, and we'll suggest a grade.

Finishes

SMC products are typically available in three finishes.

2B mill finish

A smooth, re­flec­tive finish straight from the mill. It's cost-effective and easy to clean, and suits back-of-house and utility areas.

Brushed / satin (No.4)

The familiar com­mer­cial stainless look, with fine di­rec­tion­al lines. It's good at dis­guis­ing minor scratches and fin­ger­prints in public areas.

Bead blast

A uniform matte finish with low glare. It suits ar­chi­tec­tur­al settings where re­flec­tions are unwanted, and gives a con­tem­po­rary look.

Other things to specify

• Di­men­sions: many SMC products are made to measure, such as the CD1 channel drain and GRAS grab rails.
• Options: splash­backs, tapware, mounting brackets, lockable covers and access panels.
• Com­pli­ance: AS 1428 ac­ces­si­bil­i­ty re­quire­ments where relevant, and WaterMark cer­ti­fi­ca­tion for certified product families.
• Mounting: wall, floor or recessed, and the substrate.

A sample schedule line

Twin bowl drinking fountain: SMC Stainless DFTB (or approved equiv­a­lent), grade 316 stainless steel, brushed (No.4) finish, one side AS 1428 compliant, bubblers fitted and plumbed for single con­nec­tion, concealed mounting bracket.

That one line tells the builder, plumber and supplier exactly what to deliver.

All SMC products are made to order through OPIE Man­u­fac­tur­ing Group in Western Sydney, under an ISO 9001 quality system.

Fre­quent­ly asked questions

Is grade 316 always better? Not always necessary. Grade 316 offers better chloride re­sis­tance, but grade 304 performs well in most indoor com­mer­cial en­vi­ron­ments at a lower cost. Choose for the en­vi­ron­ment.

Does finish affect hygiene? All three finishes are cleanable stainless surfaces. The choice usually comes down to ap­pear­ance, glare and how well the finish hides marks. Follow your facility's cleaning guidance.

Can I mix grades on one project? Yes. Many projects use 304 indoors and 316 for external or coastal fixtures. Just make it clear on the schedule.

Where do I find the options for each product? Each product page in the SMC store lists available grades, finishes and options, with a datasheet and DWG drawing to download and a Request a Spec­i­fi­ca­tion & Quote form.

Ready to specify? Download the datasheet and DWG, then request a price on the product page. The DFTB, for example, is available in 316. Every product in the SMC store has the same downloads and a Request a Spec­i­fi­ca­tion & Quote form.