Networking & Communications Newsletter Signup
Get the Engineering360
Stay up to date on:
Network hardware and software used to manage digital communications technologies, and the latest in LAN's and WAN's.


Product Announcement from Schroff

CALMARK™ CARD-LOK™ Retainers-Image


Schroff® CALMARK™ Series 223 and 224 CARD-LOK™ Retainers secure board module assemblies to the cold wall in cold plate/heat exchanger applications-with no torque wrench required. CARD-LOK Retainers employ a screw-actuated wedge action that locks the board module assembly in place with the use of a standard hex wrench.


  • Torque-limiting design provides a safe, firm clamping force
  • Screw-actuated wedge action reliably locks board module assemblies into place
  • Maximum thermal transfer with optimum contact between thermal paths on board and heat-sinking surface
  • Shock and vibration resistant with secure wedge action design
  • Zero insertion and extraction force on board due to screw actuation
  • Alignment spring feature returns wedge bodies to relaxed position upon unclamping
  • Two-level maintenance compliant for demanding military applications
  • Available in 5.72 mm x 6.60 mm (.225" x .260", Series 223) and 5.33 mm x 6.99 mm (.210" x .275", Series 224) profiles
  • Five-piece design provides an industry-leading clamping force of up to 350 lbs
  • Chemical Film Finish, Gold per MIL-C-5541, Class 1A
  • Chemical Film Finish, Clear per MIL-DTL-5541, Class 3, Type II
  • Black Anodize per MIL-8625, Class 2, Type II: Delivers good corrosion resistance and medium abrasion resistance
  • Hard Black Anodize per MIL-8625, Class 2, Type III: Boasts excellent corrosion and abrasion resistance
  • Electroless Nickel Plate per MIL-C-26074, Class 1, Grade B, Bright: Combines excellent corrosion protection with good electrical conductivity and low friction
  • Custom options, such as three-piece assemblies and non-standard mounting patterns and finishes


  • Military
  • Mission-Critical Electronic Devices