Tornado Washer 1/2″ I.D. Zinc Plated 12957

This is the large washer on the machine — 1/2 inch inside diameter, zinc plated — sized for the 1/2-13 fasteners that carry the heaviest loads. Part number 12957 is the genuine OEM part.

Compatible Models for the Washer 1/2″ I.D. Zinc Plated

This part is shared across a wide run of machines. On the Marathon 1200 family it is fitted to:

• Tornado 98168 12 Gallon Self Contained Carpet Extractor
• Tornado 98168 20″ Marathon 1200 Carpet Extractor (12 Gallon, 115V) — all series
• Tornado 98169 20″ Marathon 1200 Carpet Extractor (12 Gallon, 230V)
• Fits many other machines — call 763-535-0770 and we will confirm fitment for your machine.

At this size a washer is doing structural work rather than protecting a surface finish. It spreads the clamping force of a large fastener across a bearing area big enough to stop it sinking into whatever it is clamping, and it gives the nut or head a true face to turn against so the clamping force actually reaches the joint rather than being lost to friction on an uneven surface.

Which means a dished one is a real problem here, not a cosmetic one. Over-torque a large washer and it takes a permanent cup; a cupped washer then contacts on the edge of its bore, the clamping load concentrates on a narrow ring, and the joint both clamps less and damages the surface under it. Check the old one on a flat surface — any rock at all and it is finished.

Zinc plating rather than stainless tells you this position is drier than the ones that take stainless hardware, but detergent still reaches most of this machine. A washer that has pitted has lost section and therefore stiffness, which at this size is what it was chosen for.

Do not mix it into a stainless joint. Dissimilar metals in a wet, detergent-rich environment corrode galvanically at the junction, and the plated part loses.

Fit with the faces clean, the right way round if it has a burred side from punching (burr away from the bearing surface), and to a correct rather than maximum torque — over-tightening is what dished the last one.

Browse every assembly for this machine on the Tornado 98168 Marathon 1200 parts hub, and see the manufacturer’s range at tornadovac.com.

Frequently Asked Questions

What machines does the washer 12957 fit?

It is fitted to the Tornado 98168 12 Gallon Self Contained carpet extractor and the 98168 20″ Marathon 1200 in all series, and it is shared across many other machines. Call 763-535-0770 with your model and serial number and we will confirm fitment before you order.

Does a dished washer actually matter?

At this size, yes. A cupped washer contacts on the edge of its bore, so the clamping load concentrates on a narrow ring instead of a face — the joint clamps less and the surface under it gets damaged. Check the old one on a flat surface: any rock at all and it is finished.

Can I use a stainless washer instead?

Better not to. Dissimilar metals in a wet, detergent-rich environment corrode galvanically at the junction and the plated part loses. Where this machine specifies stainless it is because the position stays wet; where it specifies zinc, match it.

How do I order the Washer 1/2″ I.D. Zinc Plated (part# 12957) or get help?

You can add the Washer 1/2″ I.D. Zinc Plated (part# 12957) 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.