Used Injection Molding Machine Buying Checklist
A comprehensive inspection and evaluation checklist for purchasing a used plastic injection molding machine, injection mould machine, or plastic molding machine.
Pre-Purchase Research
- Define your required clamp tonnage (2-5 tons per sq. inch of projected area)
- Calculate required shot size and plasticizing capacity
- Determine platen dimensions and tie bar spacing for your molds
- Decide between hydraulic, all-electric, or hybrid injection molding machine
- Research market pricing (see our injection molding machine price guide)
- Identify preferred brands (Arburg, Engel, Milacron, Krauss Maffei, Nissei, etc.)
Mechanical Inspection Checklist
Clamp System
- Check platen parallelism (should be within 0.002"/ft)
- Inspect tie bars for stretch marks, scoring, or rust
- For toggle machines: check pin and bushing wear, link condition
- For hydraulic clamp: check cylinder seals for leaks
- Verify clamp force at rated tonnage
- Check mold mounting surface condition
Injection Unit
- Measure screw and barrel wear (check clearance at multiple points)
- Inspect nozzle and end cap condition
- Verify shot consistency (run 20+ shots and measure weight variation)
- Check injection pressure and speed capabilities
- Inspect hopper, feed throat, and material handling components
- For all-electric: check ballscrew and servo motor condition
Hydraulic System (Hydraulic Machines)
- Check for oil leaks at all connections, cylinders, and valves
- Sample hydraulic oil for contamination and moisture
- Verify pump pressure and flow rates
- Check accumulator pre-charge (if equipped)
- Inspect hoses, fittings, and manifolds
Control System
- Identify control brand and generation (Keba, B&R, Fanuc, Siemens, proprietary)
- Verify all screens and functions operate correctly
- Check for error logs and alarm history
- Verify data export capabilities (OPC, Euromap, etc.)
- Check if software updates are available
Documentation to Request
- Machine hours and shot counter reading
- Maintenance records and service history
- Known issues or deficiencies
- Original machine specifications
- Electrical schematics and manuals (if available)
- Reason for selling
Cost Considerations
Beyond the injection molding machine price, factor in these additional costs:
- Rigging and shipping ($2,000 - $15,000+ depending on machine size and distance)
- Installation (electrical, water, compressed air connections)
- Reconditioning (new screw/barrel, seal kits, paint) if needed
- Control upgrades if the existing system is obsolete
- Spare parts inventory (heater bands, thermocouples, nozzle tips)
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.Contact us or call 800-323-0307.
