5/8" - 11 Drill Shank Adapter

5/8"-11 Drill Adapter for Backing Plates

The Buff & Shine SP5814 is a 5/8"-11 drill adapter: a male 5/8"-11 thread on one end and a 1/4" round shank on the other. The threaded end takes a backing plate with a female 5/8"-11 insert, the most common rotary polisher thread in North America, and the shank goes into a drill chuck. Use it to polish headlights, chip repairs, sanding marks, and door handle cups. Each order is one drill shank adapter, and its usual partner is the 3" rigid backing plate (part 358).

Any backing plate with a female 5/8"-11 insert fits it. Buff & Shine pairs this adapter with its 1", 2", and 3" rigid plates, and the 3" Buffing Starter Kit boxes it with a 3-inch plate and wool and foam pads. The Semi-Flex plates, 3" through 7", thread on too, but Buff & Shine gives no drill speed for them, so run those on a rotary. For a dual action polisher with a 5/16"-24 spindle, the DA5816 threaded shank adapter takes this one's place.

What Makes it Great:

📐 Fits 3/8" and 1/2" Chucks: The 1/4" round shank sits inside the grip range of both common three-jaw chuck sizes. Push it in up to the hex collar and tighten the chuck hard so the smooth shank cannot spin when a pad catches an edge.

🔧 Hex Collar for a Wrench: A hex shoulder between the shank and the thread gives a wrench something to hold when a plate has pulled itself tight during a pass.

🎯 Spot Repair on Your Own Drill: With a 1 to 3 inch rigid plate threaded on, the drill already in your shop covers small correction work without a dedicated mini polisher.

🔁 Plates Move Between Tools: A plate spun off the adapter goes straight back onto a 5/8"-11 rotary spindle, so one set of small plates serves both machines.

Frequently Asked Questions

Will a DA backing plate fit a drill adapter?

Only if the plate has a female 5/8"-11 insert. DA plates that carry their own 5/16"-24 or M8 stud, plates that screw to the machine like FLEX's XCE plates, and rotary plates with a female M14 insert will not thread onto the SP5814.

Does a backing plate work on an impact driver?

No. An impact driver's 1/4" hex quick-change chuck only locks hex-shank bits, so it cannot hold this round shank, and its hammering action under load is wrong for polishing anyway. Use a drill with a three-jaw chuck, and set its mode collar to the drill setting, not hammer mode or a clutch number.

Why does my backing plate unscrew from my drill?

Check the direction switch first. The 5/8"-11 thread is right-handed, so forward rotation keeps the plate snug while reverse spins it off the adapter. Before you start, thread the plate on by hand until it seats against the hex collar.

Do I need the SP5814 or the DA5816 adapter?

Match the adapter to the machine. The SP5814 goes in a drill chuck, and the DA5816 screws into a dual action polisher with a 5/16"-24 spindle, not an M8 one. The plate end is the same male 5/8"-11 thread on both.

How fast can you run a backing plate on a drill?

Hold the drill to 3,000 RPM or less, the top speed Buff & Shine gives for its 1" to 3" rigid plates on this adapter. That is a ceiling, not a working speed, and Buff & Shine's suggested speeds for its 3-inch pads all sit below it. Start slow with the pad flat on the paint so the polish spreads instead of slinging, then add speed.

Specifications:

Installation (Best Practices):