A spring seat locates a spring and carries its load. It is also called a spring retainer, and when the shape is a cup, a spring cup. Balford makes spring seats two ways: formed from strip and blank by stamping and deep drawing, or turned and milled from bar. Which one is correct depends on volume, tolerance and whether the seat face has to be machined.
Spring seat, spring retainer, spring cup
These three names describe the same family of part. Spring seat is the standard engineering term and the one buyers search with. Spring retainer is used when the part also holds the spring in place in an assembly, as in a valve train. Spring cup describes a cup-shaped seat. We use spring seat in the page title and the drawing notes, and accept all three names in a request.
Stamped and deep-drawn spring seats
For volume production the seat is formed from coil or blank: blanking, drawing, ironing, piercing and coining in one progressive or transfer tool, or in single-operation draw dies. The cup wall, the flange and the seat face are produced in the same tool, so the run-out between the spring seat face and the outside diameter stays inside the tolerance stack.
- Volume: typically 20,000 pieces a year and up, where tooling cost is absorbed by the piece price
- Materials: DC01, DC04, stainless steel 304 and 316L, pure iron DT4C and DT4, brass H65
- Presses from 25 t to 350 t, maximum deep draw diameter Ø250 mm
- In-house tooling: more than 4,000 single-operation draw dies held, plus progressive and transfer dies
- Best when the seat needs a flange, a cup wall, a step or an ironed wall in one part
Machined spring seats
When the seat face or the bore needs a tolerance that forming cannot hold, or when the volume is too low for a die, a blank is prepared first — by cold extrusion, forging, cold heading or deep drawing — and then finish machined. The seat face, the bore and the locating diameter are turned and milled in one setup so they stay concentric to each other.
- Blank first: cold extrusion, forging, cold heading or a deep-drawn blank, then finish turning and milling
- Volume: prototype to tens of thousands of pieces a year
- Seat face, bore and locating diameter machined in one setup, so they stay concentric
- Cross holes, slots, flats and threads can be added without a second tooling investment
- Materials: free-cutting steel 1.7015 (11SMn30), 20MnCr5, pure iron, 1215, brass
- Best when the part is still being changed, or the tolerance is tighter than forming allows
Which route fits your spring seat
| If the part... | Route | Why |
|---|---|---|
| is a cup or a flanged cup, in volume | Stamping / deep drawing | Wall, flange and seat come from one tool; piece price falls with volume |
| needs one machined seat face on a formed body | Stamping plus a secondary machining op | Forming gives the shape, the machined face holds the tolerance |
| is turned from bar with bores and threads | CNC turning and milling | No tooling investment, changes are cheap |
| is still in development | Machined prototype, then a die | Prove the function first, commit tooling once the design stops moving |
Where spring seats are used
Solenoid and hydraulic valves, compressors, actuators, dampers and suspension assemblies, pump and valve spring packs, and any assembly where a spring has to be located with a controlled seat height. In solenoid valves the seat often also sets the air gap, so its face tolerance is a functional dimension rather than a cosmetic one.
What we check before shipping
- Seat face flatness and the run-out between the seat face and the locating diameter
- Wall thickness and ironing allowance on drawn seats
- Spring rate test and seat height on assemblies, when the customer supplies the spring
- FAI and PPAP Level 3 documentation as standard for new parts
Send a spring seat drawing for review →
Related: Solenoid valve housings · Deep drawing · CNC machining · DFM review