335311  Power, Distribution, and Specialty Transformer Manufacturing

This U.S. industry comprises establishments primarily engaged in
manufacturing power, distribution, and specialty transformers (except
electronic components). Industrial-type and consumer-type transformers
in this industry vary (e.g., step up or step down) voltage but do not
convert alternating to direct or direct to alternating current.

The data published with NAICS code 335311 include the following
SIC industries:

3548 Welding apparatus (pt)                                                    
3612 Transformers