7.94BTR Auto Trimmer Rotary Hook for Jack & Juki

The 7.94BTR Auto Trimmer Rotary Hook is a replacement rotary shuttle hook for compatible single needle lockstitch sewing machines with automatic thread trimming. It is designed for selected Jack, Juki, Brother and Siruba machines and uses the 7.94BTR / DSH2-7.94BTR / KHS12-RYP specification.

This hook is suitable for garment stitching applications involving cotton, polyester, denim, rayon, linen, knitwear, sportswear and other light to medium-heavy fabrics. Its hook point and positioning finger are designed for machines that use an under-bed thread trimming mechanism.

7.94BTR Hook for Jack A2, A3, A4, A4S, A5 & A6

This 7.94BTR rotary hook is compatible with selected Jack automatic thread trimmer single needle lockstitch machines, including Jack A2, A3, A4, A4S, A5 and A6, when equipped with the specified auto-trimmer system.

It is also compatible with selected Jack F4, F5 and C4 machines with automatic thread trimming. Always match the existing hook specification before ordering, as machine variants can use different hook configurations.

Internal linking opportunity: Link Jack Sewing Machine Parts to the relevant Jack parts category.

7.94BTR Hook for Juki DDL-8700-7 & DDL-9000 Series

The hook is designed for selected Juki single needle lockstitch machines with automatic thread trimming, including Juki DDL-8700-7, DDL-9000, DDL-9000A, DDL-9000B and DDL-9000C.

It is also specified for selected Juki DDL-5550-6 and DDL-5550-7 auto-trimmer models. The 7.94BTR hook geometry is intended to provide accurate upper-thread loop pickup while working with the machine’s thread trimming mechanism.

Compatible Brother & Siruba Sewing Machines

This rotary shuttle hook is also specified for selected Brother automatic thread trimmer machines, including S-7200A, S-7200B, S-7200C, S-7300A Nexio and PQ1500SL auto-trimmer series.

Compatible Siruba applications include L818F-A and DL720, along with equivalent auto-trimmer lockstitch machines using the 7.94BTR / DSH2-7.94BTR specification.

Key Features of the 7.94BTR Rotary Hook

Automatic Thread Trimmer Compatibility

The hook is designed for compatible single needle lockstitch machines that use an under-bed automatic thread trimming system. The positioning area and hook point are designed to work with the machine’s trimming cycle.

Precision Loop Pickup

The hook point is designed for accurate upper-thread loop pickup during high-speed sewing. Correct hook condition and machine timing can help reduce skipped stitches and thread shredding.

Smooth Hook Race Surface

The polished race surface helps reduce unnecessary friction as the hook operates. This supports smoother hook movement and consistent sewing performance.

Hardened Alloy Steel Construction

The hook uses heat-treated alloy steel intended to withstand repeated sewing operation and normal wear. Correct lubrication, needle selection and machine timing remain important for service life.

Direct Replacement Specification

The 7.94BTR / DSH2-7.94BTR / KHS12-RYP specification provides a useful reference when comparing the replacement hook with the existing part.

Machine Compatibility

Important: Compatibility depends on the machine version and hook configuration. Please verify the shape, specification and measurements of your existing hook before purchasing.

Best Fabrics for This Rotary Hook

The 7.94BTR hook is intended for compatible machines sewing light to medium-heavy fabrics.

• Cotton: Shirts, uniforms, dresses and general garment sewing.
• Polyester: Apparel, workwear and sportswear.
• Denim: Suitable for compatible denim and moderate multi-layer applications.
• Rayon: Suitable for lightweight and medium-weight garments.
• Linen: Suitable for woven linen garments.
• Knitwear: Suitable where the machine setup supports the fabric.
• Suits: Suitable for compatible woven suit fabrics.

The hook itself does not determine fabric capacity. Needle size, thread, presser-foot pressure, machine timing and machine specifications also affect sewing performance.

How to Replace the 7.94BTR Rotary Hook

1. Switch off and unplug the sewing machine before servicing.
2. Remove the needle, bobbin and required hook-area components.
3. Remove the existing rotary hook according to the machine service procedure.
4. Clean lint, thread pieces and debris from the hook area.
5. Install the replacement 7.94BTR hook in the correct position.
6. Reinstall the bobbin and other removed components.
7. Check hook timing and automatic thread-trimmer operation.
8. Test the machine at low speed before returning to normal production.

If hook timing or the thread-trimmer position needs adjustment, use the machine manufacturer’s service procedure or consult a qualified sewing-machine technician.

Signs Your Rotary Hook May Need Replacement

A worn or damaged hook can contribute to:

• Skipped stitches
• Thread shredding
• Upper-thread breakage
• Irregular loop pickup
• Thread nesting around the hook
• Inconsistent thread trimming
• Visible damage to the hook point or race
• Unstable stitching at higher speeds

These symptoms can also result from incorrect needle installation, threading, tension, hook timing or other machine problems. Check the complete sewing system before replacing the hook.

Frequently Asked Questions

Is the 7.94BTR hook suitable for automatic thread trimmer machines?

Yes. The 7.94BTR specification is designed for compatible single needle lockstitch machines equipped with automatic thread trimming. It must match the machine’s hook system and existing hook specification for proper stitch formation and thread trimming.

Which Jack machines are compatible with this 7.94BTR hook?

This hook is specified for selected Jack automatic thread trimmer models including A2, A3, A4, A4S, A5, A6, F4, F5 and C4. The machine must have the compatible auto-trimmer configuration. Verify the existing hook specification before ordering.

Which Juki machines use the 7.94BTR rotary hook?

Compatible Juki models include selected DDL-8700-7, DDL-9000, DDL-9000A, DDL-9000B, DDL-9000C, DDL-5550-6 and DDL-5550-7 automatic thread trimmer machines. Always compare the existing hook before purchase.

Can this hook be used on a normal lockstitch machine?

Do not assume it will fit. The 7.94BTR hook is specified for particular machine configurations, especially automatic thread trimmer models. Check your machine model, hook specification and existing hook design before purchasing.

What fabrics can this 7.94BTR hook be used for?

It is suitable for compatible machines sewing light to medium-heavy fabrics such as cotton, denim, polyester, rayon, linen, knitwear, sportswear and woven garment fabrics. Actual fabric capacity depends on the sewing machine and complete machine setup.

Why is my machine skipping stitches after installing a new hook?

A new hook does not automatically solve every skipped-stitch problem. Check needle condition and installation, threading, tension, hook timing and the hook point. If the issue began after installation, verify that the replacement hook is the correct 7.94BTR specification.

Does this product include the thread trimmer?

No. This product is the rotary shuttle hook assembly only. The automatic thread trimmer mechanism, trimming knives and other machine components are not included.

How many pieces are included?

The pack contains 1 × 7.94BTR rotary shuttle hook assembly.

What should I check before buying?

Check your machine model, automatic thread-trimmer configuration, existing hook shape and specification. If the specification is unclear, compare the existing part carefully before ordering.

Please verify the shape and measurements of your existing part before purchasing.