Custom Spring Manufacturing — Minuteman Spring Company
Custom Compression Springs Manufacturer
Open-coil helical springs that resist compressive forces — the most widely used spring type across virtually every industry.
Compression Springs Specifications & Capabilities
- Wire Diameter
- .008" – .312"
- End Types
- Open, Closed, Ground, Squared
- Wind Direction
- Left or Right Hand
- Coil Types
- Cylindrical, Conical, Barrel, Variable Pitch
- Materials
- Carbon steel, stainless steel, specialty alloys
- Lead Time
- Most orders ship within 10 business days
- Quoting
- Same-day quotes available
- Run Size
- Prototype (10 pcs) to high-volume production
Compression springs are open-coil helical springs designed to resist compressive forces. When compressed, they store mechanical energy and push back to their free length — making them the most widely used spring type across virtually every industry.
At Minuteman Spring Company, every compression spring is manufactured to order. We do not sell stock springs. Each spring is engineered and produced to your exact wire diameter, outer diameter, free length, load requirements, end type, and material specification — from prototype quantities to full production runs.
Our compression spring capabilities include cylindrical, conical, barrel, and variable-pitch designs. End types include open, closed, squared, and ground — each affecting how the spring seats and transfers load in your assembly.
Founded in 1946 and located in Millbury, Massachusetts, we serve aerospace and defense, medical and life sciences, automotive, industrial equipment, and electronics manufacturers throughout New England, the United States, and worldwide.
Available Materials for Custom Compression Springs
Common Applications for Compression Springs
- Aerospace & defense systems
- Medical devices & instruments
- Automotive mechanisms
- Industrial equipment
- Electronics & technology
- Energy & power systems
- Consumer products
- Agricultural machinery
Custom Compression Springs manufacturer since 1946. Same-day quoting. Ships within 10 business days.
Compression Spring Specifications We Work With
We manufacture compression springs across a wide range of sizes and configurations. Below are the general specification ranges we routinely produce. Have a requirement outside these ranges? Contact our engineering team — we handle non-standard applications regularly.
| Parameter | Standard Range | Notes |
|---|---|---|
| Wire Diameter | .004" – .625" | Finer and heavier gauges available on request |
| Outer Diameter | .062" – 6.000" | Specify OD, ID, or mean coil diameter |
| Free Length | .125" – 24.000" | Longer springs quoted case-by-case |
| Spring Rate | Custom to application | Calculated from wire dia., coil dia., and active coils |
| End Types | Open, Closed, Open & Ground, Closed & Ground | Squared ends standard; ground ends for load-bearing applications |
| Coil Direction | Right-hand or Left-hand | Right-hand is standard unless specified |
Tolerances
We manufacture to industry-standard tolerances per RMA (Rubber Manufacturers Association) and ASME guidelines. Tighter tolerances are available for precision applications — specify your requirements at time of quote.
| Dimension | Standard Tolerance | Precision Tolerance |
|---|---|---|
| Wire Diameter | ±1.0% | ±0.5% |
| Outer Diameter | ±1.5% | ±0.75% |
| Free Length | ±1.5% | ±0.5% |
| Load at Length | ±10% | ±5% |
| Number of Coils | ±0.5 coil | ±0.25 coil |
If your application requires load-verified springs, dimensional CMM reports, or first article inspection (FAI) documentation, specify this in your quote request and we will include it in the production workflow.
Materials
The right material depends on your load requirements, operating temperature, corrosion environment, and fatigue life targets. Our most common compression spring materials:
- Music Wire (ASTM A228) — Highest tensile strength of standard spring wire. Best choice for static and cyclic loads in non-corrosive environments. Cost-effective for most applications.
- Hard-Drawn MB Wire (ASTM A227) — General-purpose carbon steel wire. Lower cost than music wire; suitable for light-duty and non-critical applications.
- Oil-Tempered Wire (ASTM A229) — Better fatigue resistance than hard-drawn. Preferred for dynamic loading and automotive shock applications.
- 302/304 Stainless Steel (ASTM A313) — Corrosion-resistant. Ideal for food service, marine, and outdoor environments. Retains strength to approximately 550°F.
- 17-7 PH Stainless Steel — Higher strength and fatigue resistance than 302/304. Used in aerospace and precision instruments. Performs to approximately 650°F.
- Phosphor Bronze (ASTM B197) — Non-magnetic, electrically conductive. Used in electronics, connectors, and saltwater applications.
- Inconel 718 — Nickel-chromium superalloy for extreme temperatures and corrosive environments. Common in aerospace, oil & gas, and chemical processing.
Not sure which alloy is right for your application? See our spring materials guide or describe your operating conditions in the quote form — our engineers will recommend the correct material.
Common Use Cases
Compression springs are one of the most versatile mechanical components across industries. Here are the applications our customers most commonly bring to us:
- Automotive — Valve springs, suspension springs, brake springs, seat mechanisms, throttle return springs
- Aerospace — Actuator return springs, landing gear components, avionics assemblies requiring tight tolerances and certified materials
- Medical Devices — Drug delivery mechanisms, surgical instruments, implantable device components — often requiring 316L stainless or Inconel with full traceability documentation
- Industrial Equipment — Press tooling, conveyor systems, hydraulic valves, safety relief mechanisms
- Electronics — PCB test fixtures, connector springs, battery contacts, switch mechanisms
- Defense — Ordnance components, weapon mechanisms, ruggedized equipment requiring MIL-spec materials and documentation
- Consumer Products — Appliances, furniture mechanisms, sports equipment, hand tools
How to Order Custom Compression Springs
The fastest path to a quote is a complete print (PDF or DXF), but most customers don't have one. Here's what we need at minimum to generate an accurate quote:
- Wire diameter (decimal inches or mm)
- Outer diameter (OD), inner diameter (ID), or mean coil diameter
- Free length (uncompressed length)
- Number of active coils (or spring rate if known)
- End type (open, closed, ground)
- Material (or describe the operating environment and we'll recommend one)
- Quantity needed (prototype qty and/or production qty)
If you have a worn or broken spring you need to replace, send it to us — we'll reverse-engineer the spec and quote a replacement. Start your quote request here →
