Class Code 3805
Aircraft Engine Mfg Or Rebuilding; Auto/Truck Engine Mfg
Class Code 3805 applies to businesses that manufacture, remanufacture or rebuild aircraft, automobile and truck engines in California. The WCIRB-approved pure premium rate for September 1, 2026 is $1.378 per $100 of payroll. Knowing this classification helps employers budget for workers' comp, manage risk exposures, and remain compliant with state rules.
What Class Code 3805 Covers
This classification covers shops and plants where complete engines or major engine components are manufactured, overhauled, rebuilt or remanufactured. Operations include precision machining of crankshafts, cylinders and turbine components; balancing and alignment of rotating assemblies; assembly of engine components and accessory systems; dyno or run-up testing on engine test cells; heat treating, welding, brazing and surface treatments related to engine work. Rebuild activities that include disassembly, inspection, replacement of bearings, machining, reassembly and final testing are included. The class applies whether the work is done for aircraft engines, heavy truck diesel engines or automotive engines when the core business is engine manufacturing/overhaul rather than just vehicle assembly.
Who It Applies To
- Aircraft engine manufacturers and OEM remanufacturers
- Commercial engine overhaul and repair stations (MROs) performing engine rebuilds
- Automotive and heavy-duty truck engine manufacturing plants and remanufacturers
- Machine shop machinists and CNC operators focused on engine components
- Engine test cell technicians and assembly line engine assemblers
Common Job Duties
- Disassembling and inspecting engines and major components (crankshafts, pistons, turbine blades)
- CNC machining, grinding, honing and finishing of engine parts
- Static and dynamic balancing of rotating assemblies and flywheels
- Assembling engine blocks, heads, valve trains, fuel and lubrication systems
- Operating engine test stands/dyno cells and performing run-up testing
- Welding, brazing, heat treating and surface coating of components
- Cleaning parts with solvents, blasting, and handling heavy components with hoists
Common Injury Risks
Understanding the $1.378 Rate
The WCIRB pure premium rate of $1.378 per $100 of payroll is the base cost to cover expected claim costs for this class before insurer adjustments. To calculate pure premium, insurers multiply that rate by an employer's payroll for workers in this class (payroll/100); the final premium is then adjusted by the employer's experience modification, credits/penalties, policy limits, schedule ratings and any deductible or retrospective plans. Factors that affect what an employer actually pays include claims history, payroll mix across classifications, safety programs, and audit findings.
Cal/OSHA Compliance Requirements
Workers in engine manufacturing and overhaul are subject to Cal/OSHA Title 8 general industry requirements, including the Injury and Illness Prevention Program (IIPP), hazardous communication for solvents and metals, lockout/tagout for energized equipment, machine guarding for rotating machinery, respiratory protection where fumes or dust are present, and noise exposure limits and hearing conservation for test cells and machining areas. Engine test cells and confined spaces used during overhaul may trigger additional permit and ventilation requirements.
How Key HR Helps Employers Under Class Code 3805
As a national PEO serving California, Key HR can help classify payroll accurately under 3805, centralize payroll reporting, and manage workers' comp claims to limit loss development. Key HR provides OSHA-aligned safety programs, training (LOTO, respiratory protection, hearing conservation), return-to-work coordination and claims advocacy — actions that can improve experience modification and reduce the long-term cost of workers' comp for engine manufacturers and rebuilders.
Get a QuoteFrequently Asked Questions
Do mobile field service technicians who overhaul engines at customer sites fall under 3805?
If the technician’s primary work is engine rebuilding or remanufacturing performed on-site (disassembly, machining, reassembly, testing), they typically fall under 3805. If the work is limited to routine on-wing maintenance or engine removal/reinstallation without rebuild operations, a different maintenance or repair classification may apply. Confirm classification with your insurer or Key HR to reflect actual duties and payroll accurately.
What safety controls most reduce workers' comp claims and the experience modifier for this class?
Controls with the biggest impact include strict lockout/tagout and machine guarding, engineered noise control and a hearing conservation program for test cells, local exhaust ventilation for welding and solvent cleaning, mechanical lifting aids and hoist protocols, documented preventive maintenance and a formal IIPP with job-specific training and toolbox talks. Consistent return-to-work and light-duty programs also reduce claim durations and experience modification.
Can an engine manufacturer's facility be split across multiple class codes?
Yes. If a facility has distinct operations—for example, separate departments for engine machining (3805), general assembly of non-engine vehicle components, or electrical assembly—payroll should be allocated to the proper WCIRB codes by operation. Accurate payroll allocation is essential for correct premium calculation; Key HR can assist with audit-ready payroll tracking and classification review.
Quick Facts
- Class Code
- 3805
- Classification
- Aircraft Engine Mfg Or Rebuilding; Auto/Truck Engine Mfg
- Pure Premium Rate
- $1.378 / $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 3805?
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