Tornado Strike Screw 4 x 25 K73030840

The 4 x 25 mm Screw (part# K73030840) is the workhorse fastener on the Tornado Strike. It is used in quantity in more than one place on the machine — the back assembly takes twenty-two of them and the brush head another eight — so it is the screw most likely to go missing during a strip-down and the one worth keeping a few spares of.

Compatible Models for the Screw 4 x 25

• Tornado Strike Cordless Upright Vacuum — Model TV190-W10-U

This is a Strike-only component: Tacony’s parts records list the Tornado Strike TV190-W10-U as the single machine that takes part# K73030840, so there is no cross-model substitution to worry about when you order it.

What the Screw 4 x 25 does

Self-tapping screws into plastic bosses have a limited number of cycles in them. Each time one is driven it cuts or deforms the thread slightly, and after enough service visits the boss no longer grips. Using the correct length matters as much as the correct diameter: too short and it does not reach the full depth of the boss, too long and it bottoms out and cracks the moulding from the inside, which is a far more expensive failure than the screw.

Signs the Screw 4 x 25 needs replacing

Replace any screw that spins without tightening, that has a rounded or burred drive recess, or that shows rust or a damaged thread. If a screw will not hold in its boss but the screw itself looks sound, the boss is the problem rather than the fastener, and forcing a longer or fatter screw into it will split the housing. Panels that work loose between services usually mean several tired screws rather than one.

Fitting the Screw 4 x 25

Start every screw by hand and feel it pick up the existing thread before applying any drive — a screw that goes in crooked cuts a second thread and ruins the boss. Tighten to firm and stop; these are plastic bosses, not metal. Where several screws hold one panel, run them all up finger-tight first and tighten in a cross pattern so the panel pulls down evenly rather than being levered against one corner.

Twin City Vacuum has been selling and servicing Tornado equipment since 1956. You can browse the rest of the machine on our Tornado Strike parts pages, and the manufacturer publishes specifications at tornadovac.com.

Frequently Asked Questions

What does the Screw 4 x 25 do on the Tornado Strike?

It is the machine’s main body fastener, used in quantity to hold the back assembly together and to secure parts of the brush head.

How do I know if my Screw 4 x 25 needs replacing?

It spins without tightening, the drive recess is rounded or burred, or the thread is rusted or damaged. If a sound-looking screw will not hold, the plastic boss has failed rather than the screw — do not force a larger one in.

What models is the Screw 4 x 25 (part# K73030840) compatible with?

The Tornado Strike TV190-W10-U cordless upright vacuum, and only that machine. Tacony’s parts records list no other model that takes part# K73030840, though it is used in several places on the Strike itself.

How do I order the Screw 4 x 25 (part# K73030840) or get help?

You can add the Screw 4 x 25 (part# K73030840) directly to your cart on this page, or call us at 763-535-0770. Our staff at 5415 West Broadway, Crystal, MN 55428 has been servicing Tornado equipment since 1956 and can help confirm the right part for your machine.

Questions? Call us at 763-535-0770 or visit us at 5415 West Broadway, Crystal, MN 55428.