Materials

Specialty Materials

The alloys SCS runs, the grades within each family, and the design constants published for the ones that carry them. Compiled with our materials scientist and reviewed against what we actually hold and process.

01Materials

Material is a decision, not a default.

SCS uses an array of high-quality specialty materials suited to the most demanding applications, sourced from world-class selected suppliers in the USA, Europe and Asia.

All specialty material components manufactured by SCS can be offered with tight-tolerance PTFE or Parylene coatings, as well as gold coating.

SCS maintains a strategic stock of these specialty items to accommodate urgent enquiries.

REF-01Materials

Families

Vacuum-melted and standard stainless steels: VAR 302/304V316 LVM302 has published constants304 has published constants316 has published constants904L
Nickel-base superalloys: Inconel 600Inconel 622Inconel 625Alloy C276
Cobalt-chromium superalloys: MP35N has published constantsPhynox has published constantsElgiloy has published constants
Nickel-titanium (Nitinol), superelastic and shape-memory: Nitinol has published constants
Other specialty metals: TungstenTitanium has published constantsPlatinum-IridiumPalladium has published constants

carries published design constants

MaterialsSchedule

How these alloys behave

General alloy properties and SCS’s own published design constants. No process, tolerance or certification claims.

Vacuum-melted and standard stainless steels: Corrosion resistance and clean melt practice, at the lowest cost here. The default until fatigue or imaging says otherwise.
Nickel-base superalloys: They keep strength where heat would take the temper out of stainless. Specified for the environment, not the price.
Cobalt-chromium superalloys: The longest fatigue life here. Stiff with it: about a fifth less travel than stainless for the same load and geometry.
Nickel-titanium (Nitinol), superelastic and shape-memory: Nitinol recovers strain that would permanently set anything else here, and it does not hold a straight line rate.
Other specialty metals: Density is what a fluoroscope sees. These are specified to be found under imaging; titanium is the opposite, the lightest here.

Published design constants

As used by the SCS spring calculator. Nine of the eighteen grades carry published constants; 302, 304 and 316 share one set, as do Phynox and Elgiloy, which are the same alloy. The rest are specified against the mill certificate for the lot.

Published design constants by alloy
Alloy	RateN/mm	Shear GMPa	Densitykg/m³
MP35N	0.403	86,000	8,430
Phynox / Elgiloy	0.356	76,000	8,300
302 / 304 / 316	0.323	69,000	7,900
Palladium	0.206	44,000	12,023
Titanium	0.202	43,000	4,430
Inconel (generic)	0.370	79,000	8,280
Nitinol†	0.117	25,000	6,450

Rate is k = G·d⁴/(8·D³·Na) at 0.30 mm wire, 3.00 mm mean Ø and 8 coils. Allowable design stress is not published: it depends on temper, wire size and duty, so it is quoted per part. † Nitinol is not on this scale. It is superelastic and does not hold a straight line rate, which is generally the reason it is specified.

CoatingsPTFEParyleneGold

A coating changes the surface, not the spring.

Talk to an engineer

02Supply

Held, not just listed.

A coil of stainless wire stock on its stand at SCS

Long-term relationships with certified medical, industrial and aerospace material suppliers, a dual-source strategy on critical raw materials, and strategic safety stock on key alloys.

Talk to an Engineer