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C51 Structural Steel License (California)

California has 1,522 active C51 Structural Steel holders in the state file as of 2026-10-29¹, the 30th-largest of 64 classes with at least 200 holders. 42 of them expire by 2026-12-28.

Active holders: 1,522; 0.7% of active California licenses
Expiring by 2026-12-28: 42; 2.8% of holders
Median bond on file: $25,000; 1,520 bonds
Workers' comp exempt: 26.4%; of 1,522 with WC status

How many C51 contractors are exempt from workers' comp?

402 of 1,522 active C51 holders with a recorded status (26.4%) filed an exemption¹, against 48.7% across all California classes.

How do you check a C51 license?

Search by license number or business name on the California license lookup, which reads the same state file.

Other California license classes

D52 Window Coverings1,450
D35 Pool and Spa Maintenance1,634
D06 Construction Clean-up1,446
D34 Prefabricated Equipment1,363
C38 Refrigeration1,601
B2 Residential Remodeling1,671
D12 Synthetic Products1,729
C43 Sheet Metal1,278

All 64 classes

Sources

CA CSLB License Master (cslb.ca.gov data portal) (cslb.ca.gov, 2026-10-29)