Suggested tap drill size:
10 - 40 NS #19 drill for 74% thread

These are National Special Taps (NS) and can be difficult to find.
We purchase in quantity so are able to offer them at a reasonable price.

Please note the Rimfire spark plugs are intended for model airplane use and are not certified nor appropriate for use in ultra-lite or full size aircraft.

Flat rate shipping for all domestic orders is $7.40.

Flat rate shipping for International orders is $40. More information can be found on the FAQ page.

International buyers to pay currency exchange costs and any applicable tariffs

Any postage adjustments must be made prior to shipping.