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Powerbuilt 14mm spark plug thread repair kit with tap and inserts

Powerbuilt

Powerbuilt thread repair kit

SKU CH-4S1A-FTZBM

Rethreads damaged 14 mm spark plug holes in aluminium heads with included tap and four inserts

  • Rethreads damaged 14 mm spark plug holes in aluminium heads
  • Includes tap and four inserts for versatile repair options
  • Compatible with 3/8" drive ratchet for easy operation
  • Chrome plated finish resists corrosion and wear
  • Meets ANSI standards for reliable thread restoration

Spark Plug Hole Repair Kit

Rethreads damaged 14 millimeter spark plug holes in aluminum cylinder heads. Includes a tap and four stainless-steel inserts in three lengths: two at 7/16 inch, one at 5/8 inch and one at 13/16 inch. Designed for professional technicians and experienced DIY mechanics. Meets or exceeds ANSI standards.

Compatibility Check

Verify the cylinder head uses a 14 millimeter spark plug thread before ordering. A 3/8 inch drive ratchet or compatible drive tool is required to operate the tap. Ensure sufficient access to the damaged port for straight insertion of the tool. The kit does not alter parking brake function on any vehicle.

Sustained Use Behaviour

Chrome plating resists corrosion during repeated workshop use. Hardened tap threads maintain cutting geometry across multiple repair jobs. Inserts install permanently to restore original thread strength in soft aluminum. Lifetime warranty covers the complete kit against manufacturing defects.

Highlights

  • Rethreads damaged 14 mm spark plug holes in aluminium heads
  • Includes tap and four inserts for versatile repair options
  • Compatible with 3/8" drive ratchet for easy operation
  • Chrome plated finish resists corrosion and wear
  • Meets ANSI standards for reliable thread restoration

Specifications

BrandPowerbuillt

Questions about this item

Does the kit include everything needed to repair a 14 mm spark plug hole or must I buy a tap or inserts separately?

The kit includes the tap and four inserts — two 7/16", one 5/8" and one 13/16" — so no extra parts are required for the repair.

How do I choose between the 7/16", 5/8" and 13/16" inserts supplied in the 648421 kit?

Measure the depth of the damaged thread in the aluminium head; pick the insert length that matches or slightly exceeds that depth.

What does the ANSI compliance of the 648421 kit mean when I use it on an aluminium cylinder head?

It means the tap and inserts meet recognised dimensional and material standards, giving a reliable repair in aluminium heads.

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