The Upper Knife Presser, bearing the official part number S20577001, is a component engineered by the Japanese industrial sewing brand Brother. This specialized piece of hardware is manufactured from heavy-duty, hardened steel to withstand continuous friction, impact, and high-speed vibration during heavy production cycles. It acts as a structural clamp or holder within the fabric-trimming mechanism, specifically designed to apply precise and constant pressure to the upper cutting knife. By locking this blade rigidly into its correct position against the lower knife, it ensures a perfect shearing action that cleanly trims raw fabric edges before they pass under the needle, preventing the material from bunching, fraying, or jamming.

This part is not found on standard straight-stitch machines but is instead a key element in high-speed industrial overlock, interlock, and safety stitch setups. It is custom-built to fit Brother V-Series industrial machines, including the widely used EF4-V41, EF4-V51, EF4-V71, and EF4-V81 models, as well as the MA4-N31 and FA-V91A series. Weighing approximately fifty grams, this compact metal holder works in perfect synchronization with the surrounding hardware. When replacing this component due to uneven fabric cutting or blade instability, technicians generally inspect the matching upper knife presser plate and its fastening screws simultaneously to guarantee optimal cutting performance.

Orders are typically processed within 1–3 business days.

We ship from our Georgia, USA warehouse. If an item is temporarily unavailable in the U.S., we source it through our global supplier network and will notify you of the estimated lead time.

Free shipping is available on U.S. orders over $99.

Once your order ships, you will receive a tracking number by email.

For urgent orders or shipping questions, please contact us before placing your order.

We stand behind the quality of the products we sell.

• Genuine OEM parts are covered by the manufacturer's warranty where applicable.

• Aftermarket and generic parts are covered against manufacturing defects.

• If you receive a damaged, defective, or incorrect item, please contact us within 30 days of delivery.

• Warranty does not cover damage caused by improper installation, misuse, normal wear, or modifications.

If you have any questions, our support team is happy to help before or after your purchase.