Switchcraft M112AX
Hi-D Jax 1/4" Enclosed Telephone MIL Jack Connector


The Switchcraft M112AX is a 1/4" 2-conductor Enclosed Telephone Jack that is part of Switchcraft's Series M Hi-D Jax®.  These compactly constructed jacks permit direct cross-patching with Switchcraft, WEco and MIL-type telephone plugs and patch cords. Series M Hi-D Jax offer a choice of solder lugs or PC terminals. Both insulated and metal bushings can be specified, as well as .21" inside diameter sleeves for narrow plug fingers. Maximum contact resistance is 0.1 ohm. Springs are made of a special gold-plated copper alloy. Welded cross bar gold alloy contacts are sold separately, and available on special order.

Two-conductor type jacks mate with .25" diameter finger plugs. Tip and ring springs are gold-plated. Shunts (if used) have welded crossbar palladium contacts. Ring springs (where used with shunts) have welded crossbar palladium contacts. Tip springs (when used) do not have a contact welded to the spring. Bushing has 3/8-32-NEF-2 thread; locknut and flat washer for mounting are supplied.

Switchcraft M112AX Specifications:


  • Mounting Bushing: Nickel-plated copper alloy.
  • Housing: Molded thermoplastic, UL 94V-0.
  • Springs: Copper alloy.
  • Contacts (mil-type):
  • Tip and Ring Springs are gold-plated.
  • Shuntsprings (where used) are welded crossbar palladium.
  • Welded crossbar gold alloy contacts are sold separately on special order.
  • Contacts (commercial): Tin-plated integral contacts.
  • Sleeve Terminal: Steel, tin-plated.
  • Hardware: Supplied with one P10001 copper alloy, nickel-plated locknut and one S10221 steel, nickel-plated washer.


  • Life: 10,000 insertion/withdrawal cycles, minimum.
  • Insertion/Withdrawal Forces: Nominal plug retention on
  • 2-conductor jack is .75 pounds with .5 pounds minimum.
  • With double tips, the nominal is 1.5 pounds and 1 pound minimum.
  • Maximum Recommended Mounting Torque: 6" -pound for thermoplastic bushing.
  • Mounting Torque (for Spring Lock PC Terminal): 8" -pound for thermoplastic bushings.


  • Contact Resistance: .020 ohms maximum (initial), .050 ohms maximum (after humidity, durability exposure). Per MIL-STD-202E.
  • Insulation Resistance: 10,000 M-ohm minimum (initial), 1,000 M-ohm minimum (after humidity).
  • Dielectric Withstanding Voltage: 500 V, 60 Hz (rms) AC.
  • Contact Rating: 0.25, 48 VDC make and break, 3A carry only.


  • Thermal Range: -55°C to +85°C (non-operating); -20°C to +65°C (operating).
  • Thermal Shock: Per MIL-STD 202, method 107.
  • Humidity: Per MIL-STD 202, method 106.
  • Salt Spray: Per MIL-STD 202, method 101.

Note: All information and specifications subject to change without notice. For more information, please call your Sales Representative.

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