How to Choose the Right Machine Shop
Your complete guide to evaluating, comparing, and selecting machine shops. Make confident decisions and avoid costly mistakes.
Why Machine Shop Selection Matters
The wrong machine shop can derail your project with delays, quality issues, and cost overruns. Studies show that 34% of manufacturing delays stem from supplier issues. This guide helps you make the right choice the first time.
The 6-Step Selection Process
Define Your Requirements
Before contacting shops, clearly document your needs to ensure accurate quotes and avoid miscommunication.
Requirements Checklist:
- Part specifications (drawings, CAD files, tolerances)
- Material requirements and specifications
- Quantity (prototype, pilot, production volumes)
- Quality requirements (inspections, certifications)
- Timeline and delivery requirements
- Budget constraints
Research Potential Shops
Cast a wide net initially, then narrow down based on capabilities and requirements.
Where to Look:
- • Industry directories
- • Government databases (SAM.gov)
- • Trade associations
- • Referrals from colleagues
- • Online reviews and ratings
Initial Filters:
- • Geographic location
- • Required certifications
- • Equipment capabilities
- • Industry experience
- • Company size/capacity
Evaluate Capabilities
Dig deeper into each shop's specific capabilities to ensure they match your needs.
Key Capability Areas:
Technical Capabilities
- • Machine types and sizes
- • Tolerance capabilities
- • Material expertise
- • Secondary operations
- • Inspection equipment
Business Capabilities
- • Production capacity
- • Lead time flexibility
- • Engineering support
- • Supply chain management
- • Quality systems
Request and Compare Quotes
Get detailed quotes from 3-5 shops for meaningful comparison.
Pro Tip: Provide identical information to all shops for accurate comparison.
What to Compare:
| Factor | Why It Matters |
|---|---|
| Price | Total cost including setup, parts, shipping |
| Lead Time | Production schedule and delivery dates |
| Quality Plan | Inspection methods and documentation |
| Terms | Payment, warranty, revision policies |
| Communication | Responsiveness and clarity |
Verify Credentials
Don't skip this step – verify all claims before committing.
Verification Checklist:
- Certification validity (ISO, AS9100)
- Business registration/license
- Insurance coverage
- Customer references
- Financial stability
Government Verification
Shops with CAGE codes have been pre-vetted by the government for:
- • Financial stability
- • Physical facility verification
- • Quality systems
- • Legitimate business operations
Make Your Decision
Use a systematic approach to make the final selection.
Decision Matrix Example:
| Criteria | Weight | Shop A | Shop B | Shop C |
|---|---|---|---|---|
| Price | 25% | 8 | 6 | 9 |
| Quality Systems | 30% | 9 | 7 | 8 |
| Lead Time | 20% | 7 | 9 | 6 |
| Communication | 15% | 9 | 8 | 7 |
| Experience | 10% | 8 | 9 | 7 |
| Weighted Score | 100% | 8.3 | 7.5 | 7.7 |
Red Flags to Avoid
These warning signs indicate potential problems:
Business Red Flags
- No physical address or phone number
- Unwilling to provide references
- No certifications or quality systems
- Pressure to pay 100% upfront
Technical Red Flags
- Prices >50% below market average
- Claims unrealistic tolerances/timelines
- No clear capabilities list
- Poor communication or language barriers
Best Practices for Success
Communication
- • Establish single point of contact
- • Document all requirements
- • Set regular check-ins
- • Address issues promptly
Documentation
- • Clear drawings/specifications
- • Written quotes and terms
- • Quality requirements
- • Change order process
Relationship
- • Start with small orders
- • Build trust over time
- • Provide feedback
- • Consider partnerships
Frequently Asked Questions
What should I look for when choosing a machine shop?
Key factors include relevant certifications (ISO, AS9100, ITAR), equipment capabilities matching your needs, proven experience with similar parts, competitive pricing, reasonable lead times, and strong communication. Government verification (CAGE codes) provides additional assurance.
How many quotes should I get?
Get 3-5 quotes for comparison. This reveals market pricing, highlights capability differences, and helps identify red flags. More than 5 quotes often yields diminishing returns unless you have specialized requirements.
What certifications are important?
ISO 9001 is baseline for quality management. AS9100 is required for aerospace, ISO 13485 for medical devices, ITAR registration for defense work. NADCAP covers special processes. Industry-specific certifications ensure compliance.
How do I verify a machine shop is legitimate?
Check for physical address, business registration, certifications, customer references, and equipment lists. Government contractors with CAGE codes have been pre-vetted. Visit the facility if possible for critical projects.
What are red flags to avoid?
Red flags include no physical address, unusually low prices (>50% below others), no certifications, poor communication, unwillingness to provide references, no clear capabilities list, and pressure tactics.
Find Pre-Vetted Machine Shops
Save time with our directory of government-verified machine shops. All shops with CAGE codes have been vetted for legitimacy, quality systems, and financial stability.