Class Code 3651
Electrical Wire Harness Mfg
Class code 3651 covers companies that manufacture electrical wire harnesses, cable assemblies and looms used in automotive, aerospace, medical, appliance and electronics products. The September 1, 2026 approved pure premium rate for California is $3.581 per $100 of payroll. As a PEO serving California from our Orlando headquarters, Key HR helps employers correctly classify work, manage risk and control workers' comp costs for this specialized light-manufacturing exposure.
What Class Code 3651 Covers
This classification applies to operations that cut, strip, crimp, solder, terminate and assemble insulated wires into harnesses, multi-branch cable assemblies or looms. Typical processes include hand and bench assembly, high- and low-volume automated crimping, connector insertion, application of heat-shrink tubing, taping and bundling, potting or epoxy encapsulation, and electrical testing (continuity, hipot, insulation). It covers manufacture of harnesses for automotive wiring harnesses, aircraft and aerospace cable assemblies, medical device cables, appliance wiring and industrial control harnesses. Activities performed in cleanrooms for medical/aerospace parts remain included when the primary operation is wire harness fabrication. The classification excludes primarily finished-product electrical equipment manufacturers whose operations are dominated by sheet metal, machining or electrical apparatus production rather than wire assembly.
Who It Applies To
- Contract electronics manufacturers doing cable and harness assembly
- Automotive wiring harness shops and tier suppliers
- Aerospace and defense cable/harness fabricators
- Medical device cable and probe assembly shops
- Small cable assembly shops producing looms and multi-branch harnesses
Common Job Duties
- Cutting wire to length and stripping insulation with hand tools or automatic strippers
- Crimping terminals with hand or pneumatic crimping machines and indexing fixtures
- Soldering terminals and joints using soldering irons, hot air or wave solder processes
- Inserting wires into connector housings, routing and bundling with tape, ties or sleeving
- Applying heat-shrink tubing, adhesives, potting compounds or epoxy encapsulation
- Electrical testing: continuity, insulation resistance, hipot testing, and functional checks
- Labeling, packaging and visual/QA inspection of finished harness assemblies
Common Injury Risks
Understanding the $3.581 Rate
The approved pure premium rate of $3.581 per $100 of payroll represents the portion of premium based solely on expected claim costs for the class. Insurers multiply this loss cost by their adjustments (expense and profit multipliers), then apply your payroll/100 and experience modification, schedule credits/penalties, and any deductible or retrospective programs to calculate the final premium. On-site safety, claims history, payroll mix and classification accuracy materially affect the premium you ultimately pay.
Cal/OSHA Compliance Requirements
California employers must maintain an effective Injury and Illness Prevention Program (IIPP) and comply with Cal/OSHA Title 8 general industry standards. For wire harness manufacturing, pay particular attention to ventilation and local exhaust for soldering fumes and flux, proper machine guarding and lockout/tagout when servicing crimpers or automated equipment, PPE for eye and hand protection, and Hazard Communication controls for solvents, adhesives and potting compounds. Ergonomics and workstation design to reduce repetitive strain are also critical components of a compliant safety program.
How Key HR Helps Employers Under Class Code 3651
A PEO like Key HR can centralize workers' comp administration, secure competitive loss-cost multipliers, and implement targeted safety programs (soldering fume controls, ergonomics, lockout/tagout and tool guarding) to lower claims. We provide claims management, return-to-work programs, safety audits and training specific to wire-harness operations, helping improve your experience modification and reduce long-term premium exposure.
Get a QuoteFrequently Asked Questions
How do I know if my shop should be coded to 3651 or another manufacturing class?
Use 3651 when the primary operation is fabricating wire harnesses and cable assemblies (cutting, stripping, crimping, soldering, inserting into connectors and testing). If your facility primarily does machining, sheet metal, or final appliance assembly with only incidental wiring, a different class may apply. Key HR can review operations, payroll distribution and job duties to confirm proper classification.
What practical steps reduce workers' comp claims in wire harness manufacturing?
Implement ergonomic workstations, adjustable benches and chairs, job rotation, anti-vibration tools, fume extraction for soldering, machine guarding and PPE programs, plus targeted training on safe crimping and soldering techniques. Early-return-to-work modified-duty plans and prompt claims reporting also limit indemnity exposure.
Can Key HR help lower my rate or experience mod for class 3651?
Yes. Key HR delivers claim advocacy, safety program development, on-site or virtual training, and return-to-work coordination to improve loss performance. Over time those measures, along with negotiated insurer multipliers and payroll accuracy, can lower your effective premium and experience modification.
Quick Facts
- Class Code
- 3651
- Classification
- Electrical Wire Harness Mfg
- Pure Premium Rate
- $3.581 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
Manage Workers' Comp Through a PEO
Key HR provides pay-as-you-go workers' comp for California employers — no large deposits, no audits, better rates.
Get a Quoteor call (800) 922-4133Ready to Simplify Workers' Comp for Class Code 3651?
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