Toolwiz Spark Plug Gap Tool — 32-Blade Steel Feeler Gauge, Black compact gapper for accurate ignition tuning

Toolwiz Spark Plug Gap Tool is a compact hand tool that safely and accurately reduces spark plug electrode gaps and comes with a 32-blade steel feeler gauge for precise setup.

If you service engines, motorcycles, lawn equipment or perform routine tune-ups, setting the correct spark plug gap matters for consistent ignition and smooth running. The Toolwiz kit combines a simple mechanical gapper that compresses the electrode with a hardened, dual-marked 32-blade feeler gauge so you can measure and reduce gaps to the specification your engine requires.

How does the Toolwiz gap tool change a spark plug gap?

The tool uses a controlled compression method: seat the plug in the holder, select the feeler blade, and slowly turn the knurled knob to press the center electrode toward the ground electrode until the target clearance is reached. It only reduces gaps — it cannot bend the electrode outward to enlarge a gap.

• Place the plug correctly into the tool holder before adjusting.
• Use a slightly smaller feeler blade than your target gap for best retention.
• Turn the knob slowly and recheck the gap after allowing the electrode to settle.

Which spark plugs are compatible with this kit?

Toolwiz is designed for most standard 10mm, 12mm, 14mm and 16mm thread spark plugs encountered in cars, motorcycles, small engines and power equipment. It does not fit 18mm threaded plugs, or specialty long-reach and short-reach plugs.

• Works with most non-preset gap spark plugs.
• Not suitable for 18mm thread or unusual reach designs.
• Iridium and platinum plugs commonly come pre-gapped and usually don’t need adjustment.

How accurate and durable is the included feeler gauge?

The included 32-blade feeler gauge is made from 65 manganese steel, hardened and polished for long-term precision. Each blade is dual-marked in inches (0.001"–0.040") and millimeters (0.03–1.0mm) so you can verify common automotive and small-engine gap specs quickly.

• 32 blades cover a wide range of gap sizes for most tuning needs.
• Hardened steel resists wear so measurements stay accurate over time.
• Dual markings make cross-referencing metric and imperial specs simple.

What practical tips improve results when adjusting gaps?

Electrodes can spring back slightly after being bent, so using a slightly smaller feeler blade than the intended gap helps ensure the finished clearance matches the specification. Always clean the plug and inspect the electrode before and after adjustment, and avoid over-compressing fragile or fine-wire center electrodes.

• If your target is 0.030", try adjusting with 0.028" then recheck.
• Avoid repeated heavy bending on iridium or platinum tips to prevent damage.
• Re-measure after seating the plug in the cylinder to confirm final clearance.

Who is this for? The Toolwiz Spark Plug Gap Tool and 32-blade feeler gauge kit suits DIY mechanics, fleet technicians, small-engine repairers and hobbyists who need a reliable, portable solution to reduce spark plug gaps with controlled force. It’s a practical choice for anyone who wants quick, accurate gap reduction on common 10mm–16mm plugs and prefers a hardened steel gauge with both imperial and metric markings. Note: it’s not intended for 18mm or specialty reach plugs and won’t expand gaps — only compress them.