EHC Knobs - Control Knobs - Round Knob Locks Details

EHC Self Locking Control Knobs feature a Push-to-Turn action & forms part of the EHC Round Knob Locks, available with custom options.

These EHC Knob Control Locks offers Military Grade options, with added protection against stock & vibration, with zero backlash.

• Military Knob Lock Controls
• Sprag Clutch Design
• Custom Options

The EHC Knob Control Locks offer accurate functions, ideal for MS91528 applications & should be fully depressed before movement.


The EHC Knob Locks are positive friction locking devices for holding precise or critical control settings under conditions of shock and vibration. These EHC Knob Control Locks are also useful where there is danger of accidental jarring or manual contact.

With special splash-proof versions available, featuring molded rubber inserts to prevent water leakage down into the control and also serve as an effective dust seal.


• Positive friction locking system
• Resists shock, vibration, or accidental movement
• Tested under salt spray, humidity, and temperature conditions
• Occupies minimum panel space
• Used with standard off-the-shelf control knobs: 700,.900 and1.250 diameter knobs
• No special mounting hardware or tools required
• Special water and dust-tight models available
• Made of highest quality materials
• Available in three sizes in either mirror or matte finish


Part No:
               MS91528     Type:         Finish:      Diam A:     Diam B:    Thread: 
.700 Diam.Knob
                                               Standard       Mirror            1"             .721         3/8-32
KL701                                     Standard       Mirror            1”             .721         3/8-32
KL701G                  1CC2B      Standard       Matte            1”              .721        3/8-32
KL702                                     Standard       Mirror            1”             .721         1/4-32
KL702G                  1CC2G      Standard       Matte            1”             .721         1/4-32
KL703                                   Splash Proof   Mirror             1”             .721        3/8-32
KL703G                  1DD2B    Splash Proof    Matte            1”             .721        3/8-32

.900 Diam.Knob
                        Type:         Finish:      Diam A:     Diam B:    Thread:
KL901                                      Standard       Mirror         1-5/16”         .928         3/8-32
KL901G                   2CC2B      Standard       Matte         1-5/16”         .928         3/8-32
KL902                                    Splash Proof    Mirror        1-5/16”         .928         3/8-32
KL902G                   2DD2B    Splash Proof    Matte         1-5/16”         .928        3/8-32

1.250 Diam.Knob
                       Type:         Finish:      Diam A:     Diam B:    Thread:
KL1251                                    Standard        Mirror          1-5/8”         1.269       3/8-32
KL1251G                 3CC2B      Standard        Matte          1-5/8”         1.269       3/8-32
KL1252                                 Splash Proof     Mirror          1-5/8”          1.269      3/8-32
KL1252G                 3DD2B   Splash Proof     Matte          1-5/8”          1.269      3/8-32

*The above MS91528 designations are for reference only. Series of knobs used in conjunction with knob lock are MS91528, EH71 and Contemporary.

An eighth turn of the fluted skirt locks the control knob by forcing a rubber bushing against its lower surface. A critical control setting is not affected. An eighth turn to the left frees the knob to rotate freely. Used primarily with potentiometers and similar variable controls, knob locks mount directly to threaded control bushings replacing the nuts and lock washers usually supplied.