• tensionpro_mcaps

    Quick and easy to install.

MCAP metal thread caps

MCAPs are screw-on metal thread caps that protect stud bolts and nuts from thread damage, dirt and corrosion. Quick and easy to install, they extend the life of bolts and nuts, which can save maintenance time when bolting is disassembled for servicing. This reduces plant downtimes and saves time and money.

MCAPs are widely used in refineries, petrochemical plants, LNG plants, offshore platforms, wind turbines and other steel structures. They can be installed on heat exchangers, reactors and process equipment operating at temperatures up to 550°C and over, where standard plastic caps are not suitable.

The caps do not degrade due to UV and can give long term protection to foundation bolts and other critical bolts exposed to the environment.

MCAPs feature a simple screw on system. An indent on the cap is used to match the thread size so it can be quickly and firmly attached to the stud thread. MCAPs are designed to be installed manually with no extra tools required. They can be easily removed when needed.

Standard MCAP designs are held in stock for quick delivery. The caps can also be custom made to suit any applications with a very fast turnaround.


  • Protect bolt and nut threads
  • Prevent corrosion
  • Faster maintenance and repairs
  • Avoid time-consuming removal of seized bolts
  • Save time and money on plant downtimes
  • High temperature compatible
  • Simple screw on system for installation and removal
  • Reusable and long-lasting
  • Wide range of standard sizes plus custom designs
  • Fully customisable
  • Available from stock for quick delivery


  • 1½” to 6”, M12 to M100 (UN/metric ISO threads)
  • Stud only or stud and nut configuration
  • Optional materials: Stainless steel, carbon steel and aluminium
  • Optional surface finishes: zinc electroplated, nitride, chemically blacked
  • Optional grease nipple
  • mcap

    Stud only carbon steel

  • mcap

    Nut and stud version

  • mcap

    Stud only stainless steel

  • mcap

    Nut and stud version

Data Sheets

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