Standard Press now runs a full 316 stainless press system alongside its copper range: fittings, valves, unions, flange adaptors and pipe supports from 15mm right up to 168.3mm. The first question most plumbers ask is a fair one. At roughly four times the price of copper per fitting, when does stainless actually make sense? Here's the honest answer, using the real numbers from the range.
What the stainless system is
- Material: 316L stainless steel (1.4404) fittings.
- Jaws: M-profile. Not the V-profile jaws used on Standard Press copper. More on that in why your copper press jaws won't do stainless.
- Seal: black EPDM as standard, for potable water, rated -20°C to +110°C.
- Tube: 304 or 316 metric stainless tube to AS 5200.053, in 15, 22, 28, 35, 42, 54, 66.7, 76.1, 88.9, 108 and 168.3mm.
- Pressure: listed maximum working pressure of 1600 kPa at all sizes, with higher figures quoted for 15mm and 22mm (size and tool dependent).
Browse the full stainless steel press fittings range.
The price gap, in real numbers
A 15mm Standard Press copper water coupling is $1.89. The 15mm 316 stainless press coupling is $8.27, about 4.4 times as much, and that's before you price stainless tube against copper tube. On a typical house rough-in with dozens of joints, the gap adds up fast. For most residential hot and cold work, copper press is still the sensible choice.
The gap matters less as the job gets bigger and more specialised. Fittings become a smaller share of the total against labour, plant and downtime, and on some services copper stops being an option at all.
Where 316 stainless earns its price
Coastal and corrosive sites
316 carries molybdenum, which gives it better resistance to chlorides than 304. That's why it's the grade specified for salt-spray exposure, pool plant rooms and wash-down areas. It's the same logic we covered for 304 vs 316 floor wastes and 316 outdoor tapware.
Hygiene-critical and process pipework
Food and beverage, commercial kitchens, labs and healthcare plant: stainless is often the expected material, and it cleans down and inspects well where pipework is exposed.
Large bore plant room work
The range runs to 168.3mm, with flange adaptors in AS 2129 Table E and ANSI 150 for pumps, backflow assemblies and plant. Pressing a large-bore joint is far quicker than welding or grooving it, and it's flame-free, so no hot work permit.
Exposed pipework that has to look right
Commercial fit-outs and plant rooms where the pipe is on show, and where copper would tarnish or need painting.
Where copper is still the better choice
- Standard residential hot and cold water. The cost difference per joint is hard to justify.
- Solar collector circuits. The stainless range's standard EPDM seal is rated to +110°C. The copper solar press range with red FKM seals is rated to +170°C. See EPDM vs FKM press seals.
- When the crew only has V-profile jaws. A one-off small stainless job may not justify buying M-profile jaws.
Sort these out before you switch a job to stainless
- Jaws. M-profile, and confirm with your tool maker that the tool and jaws are approved for stainless press.
- Tube. Source 304 or 316 metric tube to AS 5200.053 in the matching outside diameter. See stainless press sizes explained.
- WaterMark. The listings state AS/NZS 4020 compliance for potable-water contact materials. A drinking-water install in Australia also needs WaterMark-certified products, so confirm the certification details with PSA before you specify.
- Transitions. A stainless press fitting doesn't press onto copper tube, and copper fittings don't press onto stainless. Move between the two through a threaded connection. See stainless press to thread.
Frequently Asked Questions
Is stainless press more expensive than copper press?
Yes. At 15mm, the Standard Press stainless coupling is $8.27 against $1.89 for the copper water coupling, before tube. The premium pays off on corrosive, hygiene-critical, large-bore and exposed work rather than standard house plumbing.
Can I use my copper press jaws on stainless press fittings?
Not for this range. Standard Press copper fittings are V-profile; the 316 stainless range is M-profile and needs M-profile jaws approved for stainless.
Is 316 stainless press suitable for hot water?
The standard black EPDM seal is rated -20°C to +110°C, which covers normal hot water services. For solar collector circuits, the copper solar press range with red FKM seals is rated higher, to +170°C.
What tube do stainless press fittings need?
304 or 316 metric stainless tube to AS 5200.053, in the matching outside diameter from 15mm to 168.3mm.