An official website of the United States government
Here's how you know
A .mil website belongs to an official U.S. Department of Defense organization in the United States.
A lock (lock ) or https:// means you’ve safely connected to the .mil website. Share sensitive information only on official, secure websites.

Machinist's Mate (MM)

 
MM Rating Badge
MM Community Overview
MM Career Path

                    
General Description 
Machinist's Mate (Surface) (MM) Machinist's Mates operate and maintain steam turbines and reduction gears used for ship propulsion and auxiliary machinery such as turbogenerators, pumps and oil purifiers. They also maintain auxiliary machinery outside of main machinery spaces, such as electrohydraulic steering engines and elevators, refrigeration plants, air conditioning systems and desalinization plants. They may also operate and maintain compressed gas producing plants.
 
What They Do
The duties performed by MMs include: aligning piping systems for oil, water, air and steam, and controlling the operation of ship boilers and steam turbines used for ship propulsion and service systems; controlling operation of turbogenerators used to produce electrical power; leaning, adjusting, testing and performing other preventive maintenance on a ship's boilers, main engines, turbogenerators and other auxiliary machinery including steering engines, elevators, winches, pumps and associated valves; operating and maintaining desalinization plants (distilling plants) to make fresh water from sea water; maintaining refrigeration plants, air conditioning systems and galley equipment; repairing or replacing valves, pumps, heat exchangers, compressors, steam turbines and hydraulic or pneumatic control devices; making entries in and analyzing machinery operating records and reports.
 
Working Environment
Machinist's mates work within the hull of a ship in fire rooms, boiler rooms, engine rooms or shops. These locations are sometimes hot and noisy. MMs may be required to perform some heavy physical work. They must be able to work closely with others and, in some cases, with limited supervision.

Requirements ASVAB (Waivers are considered on a case-by-case basis)
VE + AR + MK + AS = 195 OR VE + AR + MK + AO = 200
Must have normal hearing

Normal hearing required. Frequencies: 3000hz 4000hz 5000hz 6000hz Average hearing threshold level in these four frequencies must be less than 30db, with no level greater than 45db in any one frequency. If hearing level exceeds these limits, the applicant is enlistment ineligible for the rating.  
 
  Veterans Crisis Line - Dial 988  Safe Helpline  NCIS Tips  Sexual Assault Prevention & Response  NFAAS
 

Need Career, Pay or Personnel help?
Call MyNavy Career Center: 833.330.MNCC,
or 901.874.MNCC (DSN 882.6622)

Email MNCC, MNCC Chat 
Comments or Suggestions about this website?
Email the Webmaster

NAVY PERSONNEL COMMAND
5720 Integrity Drive
Attn: PERS-### or BUPERS-###
Millington, TN 38055-0000

Search This Site
This is an Official U.S. Navy Website

Site Map | FOIA | U.S. Navy | U.S. Navy Recruiting
No Fear Act | USA.gov | Privacy Policy
Open Government | Plain Writing Act
Veterans Safe Helpline | Navy SAPR | NETC 
Accessibility/Section 508 | Information Quality
NCIS Tips | Privacy Program | Veteran CrisisLine
|