Used Injection Molding Machine Buying Checklist
By Meadoworks | February 2026 | 10 min read
Key Takeaways
- Hours alone don't tell the story — maintenance history and component condition matter far more
- 4 systems to inspect: clamp, injection unit, hydraulics (if applicable), and controls
- Shot consistency test (20+ shots) is the single best indicator of overall machine health
- Budget beyond purchase price: rigging, installation, possible reconditioning and controls upgrades
- Inspect in person when possible, or hire a third-party inspector for sight-unseen purchases
Buying a used injection molding machine — whether a small toggle or a large two-platen — is a major capital decision. A well-chosen machine can run productively for decades; a poorly-vetted one can cost more in repairs and downtime than it saved at purchase. This checklist walks through everything from pre-purchase research to mechanical inspection, documentation requests, and the often-overlooked costs that come after the sale.
Pre-Purchase Research
Before you start shopping, lock in your specifications. Buying a machine that's slightly oversized is far less costly than buying one that's under-spec for your application.
Define Tonnage
2–5 tons per square inch of projected part area. Add safety margin to avoid running at 100% capacity in production.
Calculate Shot Size
Required shot weight plus 20–30% margin. Verify plasticizing capacity matches your cycle time requirements.
Determine Platen Size
Platen dimensions and tie-bar spacing must accommodate your existing molds plus any future tooling.
Choose Machine Type
Hydraulic (lower up-front cost), all-electric (energy-efficient, precise), or hybrid (balanced).
Research Pricing
Benchmark against the market with our injection molding machine price guide before negotiating.
Identify Brands
Arburg, Engel, Milacron, Krauss Maffei, Nissei — preferred brands shape parts availability and resale.
Reference Pricing First
Before negotiating, benchmark current market values with our used injection molding machine price guide. Sellers often quote optimistic numbers based on what they paid years ago, not current market reality.
Mechanical Inspection Checklist
A machine's long-term value lives in its mechanical condition. Walk through each subsystem methodically — don't let a clean coat of paint distract you from worn components underneath.
Clamp System
- Platen parallelism within 0.002"/ft
- Tie bars free of stretch marks, scoring, or rust
- Toggle: pin/bushing wear and link condition
- Hydraulic clamp: cylinder seals leak-free
- Verify clamp force at rated tonnage
- Mold mounting surface flat and undamaged
Injection Unit
- Screw and barrel wear measured at multiple points
- Nozzle and end cap in good condition
- Shot consistency: 20+ shots within tight weight tolerance
- Injection pressure and speed meet spec
- Hopper, feed throat, and material handling clean
- All-electric: ballscrew and servo motor sound
Hydraulic System
Hydraulic and hybrid machines only.
- No oil leaks at connections, cylinders, or valves
- Hydraulic oil clean — no contamination or moisture
- Pump pressure and flow rates match spec
- Accumulator pre-charge correct (if equipped)
- Hoses, fittings, and manifolds in good shape
- Reservoir level and breather filter inspected
Control System
- Control brand and generation identified (Keba, B&R, Fanuc, Siemens, proprietary)
- All screens and functions operate correctly
- Error logs and alarm history reviewed
- Data export capability verified (OPC, Euromap, etc.)
- Software updates / parts support still available
- All sensors, encoders, and thermocouples functional
Watch for Obsolete Controls
An older machine with an unsupported control system can become unusable if a board fails. Before buying, verify the control generation, parts availability, and whether reasonable upgrade paths (Mattec, Hilectro, Conair retrofits) exist.
Documentation to Request
Always get key documentation in writing before closing. Sellers who can't — or won't — provide records are a yellow flag.
- Machine hours and shot counter reading
- Maintenance records and service history
- Known issues or deficiencies disclosed in writing
- Original machine specifications sheet
- Electrical schematics and operator/service manuals
- Reason for selling (and reference for prior owner)
Total Cost of Ownership
The purchase price is rarely the full investment. Plan for these additional costs to avoid post-purchase surprises.
| Cost Category | Typical Range | Notes |
|---|---|---|
| Rigging & Shipping | $2,000 – $15,000+ | Depends on machine size, distance, and need for crane / dismantling |
| Installation | $1,500 – $10,000 | Electrical, water, compressed air, and material drying connections |
| Reconditioning | $5,000 – $50,000+ | New screw/barrel, seal kits, paint — only if needed |
| Control Upgrade | $10,000 – $40,000 | If existing system is obsolete or unsupported |
| Spare Parts Inventory | $1,000 – $5,000 | Heater bands, thermocouples, nozzle tips, common consumables |
Frequently Asked Questions
What should I inspect on a used injection molding machine?
Key inspection points include screw and barrel wear, platen parallelism, tie bar condition and stretch, hydraulic system for leaks, toggle mechanism, shot consistency, and control system function. Always request machine hours and shot counter readings.
How many hours is too many for an injection molding machine?
There is no hard cutoff. A well-maintained machine with 50,000 hours can outperform a neglected machine with 15,000 hours. Focus on maintenance records, component condition, and overall machine performance rather than hours alone.
Should I buy a used injection molding machine sight unseen?
While Meadoworks provides detailed specifications and photos, we strongly recommend inspecting machines in person or hiring a third-party inspector when possible. For machines purchased sight unseen, ensure the dealer provides honest condition reports and a clear return policy.
Need Help Evaluating an Injection Molding Machine?
Meadoworks has 50+ years of experience buying and selling injection molding machines. Our team can help you evaluate specifications, inspect equipment, and negotiate fair prices.
