Enlisted Rating Insignia

The enlisted rating badge for Petty Officer Third Class and above consists of two parts. The chevrons indicated the pay grade (rate). Between the chevrons and the eagle is a speciality insignia indicating the Sailor's job speciality (rating). These insignia appear in white on blue uniforms and Navy blue on white uniforms. This table shows the rating insignia for engineering and hull specialities. The other groups are Administration/Medical/Dental, Aviation, and Construction.

Engineering and Hull Specialties

BT - Boiler Technician	DC - Damage Controlman	EM - Electrician's Mate	EN - Engineman
GS - Gas Turbine System Technician*	HT - Hull Maintenance Technician	IC - Interior Communications Electrician	IM - Instrumentman
ML - Molder	MM - Machinist's Mate	MR - Machinery Repairman	OM - Opticalman
PM - Patternmaker	Notes
	*Note: "Gas Turbine System Technician" is used at paygrade E-9 only. Leading to GS: GSE (Gas Turbine System Technician - Electrical) and GSM (Gas Turbine System Technician - Mechanical).