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TWI-321 – 5/16″ CAPACITY


TWi-321: 5/16″ Capacitor Discharge System

The TW-i series of capacitor discharge stud welders incorporates the latest solid state technology into a compact, light-weight, and rugged CD stud welder. This full line of equipment is capable of welding pins, cup head pins, and CD studs ranging from 14-gauge up to 3/8” full-flanged stainless steel studs.

TW-i 321 Manual

TWi Flyer



  • —NEW FEATURE— Intuitive Touchscreen Interface with Preset values for fast, accurate, and repeatable weld settings
  • —NEW FEATURE— Set-Point Discharge: Unit discharges directly to a new set point without needing to discharge completely
  • —NEW FEATURE— Universal Input Voltage: Plug and play, no need to re-tap the machine for 110V or 220V input voltages
  • —NEW FEATURE— Low input voltage capability enables operation with long extension cords
  • —NEW FEATURE— Contact and Trigger Indicators for fast troubleshooting of hand tool and weld cable maintenance issues
  • —NEW FEATURE— Thermal and Voltage protection indicators to protect the unit from damage due to overheating or poor input power
  • Rigid internal construction minimizes the possibility of components coming loose during rough handling or operations
  • Sheet metal is powder-coated for greater durability, texture, and appearance.
  • Hand tool has been ergonomically designed to reduce operator fatigue for increased welding efficiency
  • Hand tool has an adjustable internal spring to apply the correct spring pressure for every welding application
  • Hand tool can be configured for “B” collets, “CI” collets, Euro collets, or standard tapered chucks.
  • The TWi-321 CD Unit weighs less than most other available models for ease of carrying.


TWi-321 Specifications

  • Size/Dimension: 14” L, 10.5” W, 11.5” H  356mm x 267mm x 292mm
  • Weight: 20.8 lbs.
  • Capacitance: 114,000µF
  • Weld Energy: 2280 Watt-seconds
  • Weld Range: 14 gauge through 5/16″ stainless
  • Duty Cycle: 14 studs per minute @ 5/16″ settings
  • Primary Power: 85-250 VAC, 6.0-2.0A, 50/60Hz
  • 10A Fast Acting Fuse
  • Charge Voltage: 35-200 VDC
Additional Information
Weight 45 lbs
Dimensions 21 × 13 × 12 in