Internal Tooth #10 Lock Washer 7CY001

The Internal Tooth #10 Lock Washer (part# 7CY001) is a genuine Tacony OEM replacement part from the brush assembly of the Tornado Marathon SE 900 self-contained carpet extractor. It is the toothed lock washer sized for #10 fasteners, biting inward to resist loosening.

What the Internal Tooth #10 Lock Washer does

A toothed washer only locks when its bore matches the fastener. On a #10 screw the teeth are small and there is very little margin, so a washer one size up sits loose and cocks under the head, and one size down will not pass the shank at all. Getting the #10 washer onto the #10 screw is most of what makes this part work, which is why it carries its own number rather than being lumped in with the larger one.

When to replace the Internal Tooth #10 Lock Washer (7CY001)

Replace it whenever the joint is opened, since the teeth take a set the first time they are tightened. Bin any washer that is flat, dished, cracked, or corroded enough that the tooth edges have gone dull.

Internal Tooth Lock 7CY001 — fitment and installation notes

Fit it directly under the turning part so the teeth see the load, and use it with a plain washer beneath where the surface underneath is soft or finished. Keep the #10 and larger toothed washers separated during a strip-down, because in a tray they look identical and a mismatched one does nothing. Tacony builds the Tornado Marathon SE 900 and the Powr-Flite Prowler PFX900S on a single machine platform, so this component carries across both brands rather than belonging to either one. It is a shared Tacony component and may fit additional models beyond those listed — call us and we will confirm against your serial number.

Compatible Models for the Internal Tooth #10 Lock Washer

• Tornado Marathon SE 900 — Model 98170
• Powr-Flite Prowler PFX900S
• Powr-Flite PFX900SG

Twin City Vacuum has been selling and servicing commercial floor-care equipment since 1956 from 5415 West Broadway, Crystal, MN 55428. We stock genuine Tacony parts and ship nationwide. Browse the full Tornado 98170 parts catalogue, or see the manufacturer at tornadovac.com.

Frequently Asked Questions

What does the Internal Tooth #10 Lock Washer do on the Tornado Marathon SE 900?

A toothed washer only locks when its bore matches the fastener. On a #10 screw the teeth are small and there is very little margin, so a washer one size up sits loose and cocks under the head, and one size down will not pass the shank at all. Getting the #10 washer onto the #10 screw is most of what makes this part work, which is why it carries its own number rather than being lumped in with the larger one.

How do I know if my Internal Tooth #10 Lock Washer needs replacing?

Replace it whenever the joint is opened, since the teeth take a set the first time they are tightened. Bin any washer that is flat, dished, cracked, or corroded enough that the tooth edges have gone dull.

What models is the Internal Tooth #10 Lock Washer (part# 7CY001) compatible with?

The Tornado Marathon SE 900 (Model 98170), the Powr-Flite Prowler PFX900S and the PFX900SG. It is a shared Tacony part and may fit further models; call us to confirm.

How do I order the Internal Tooth #10 Lock Washer (part# 7CY001) or get help?

You can add the Internal Tooth #10 Lock Washer (part# 7CY001) 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.