Check the machine's part number first
Brother lists the SA156 clear bobbin as 7/16 inch deep and the SA155 as 3/8 inch deep. The SA156 is also identified as a Class 15 bobbin. Compare those labels with the manual for your exact machine; do not choose by appearance alone.
See Brother's SA156 product details, SA155 product details, and its Class 15 bobbin guidance.
Compare the part numbers, not just the names
| Part | Published depth | Use it when |
|---|---|---|
| SA156 / Class 15 | 7/16 inch | Your manual or Brother support page names SA156 or Class 15. |
| SA155 / Size L label | 3/8 inch | Your manual names SA155 or the matching bobbin type. New brothread labels its prewound version Type L (SA155); that label alone is not a fit guarantee. |
Brother's SA155 listing calls it a 9.4-size embroidery bobbin; New brothread labels its prewound version Type L (SA155). Follow the exact instructions for your machine rather than treating seller labels as a universal cross-brand standard.
Prewound options by labeled format
These are options to compare after you have confirmed the part number. Check the listing's current package details before ordering.
New brothread's Size A SA156 product page and Type L SA155 product page show how the maker labels these formats.
As an Amazon Associate we earn from qualifying purchases.
For a machine that specifies SA156
New brothread 144-piece Size A SA156 white prewound bobbins
This listing identifies the pack as Size A/SA156 and white. Confirm those markings against your manual before ordering.
The listing does not establish fit for every machine.
For a machine that specifies Type L / SA155
New brothread 25-piece Type L SA155 assorted-color prewound bobbins
The listing names the Type L/SA155 format and assorted colors. Match the format to the exact part number in your machine instructions.
Check the exact variant and machine model before ordering.
Choose the thread separately
Bobbin size describes the physical format. Thread is a separate choice. Once the format matches your machine, follow its manual and the design instructions for thread type and weight.
Prewound listings may offer several thread variants under one product name. Check the exact option and package label instead of assuming that a bobbin-size label also identifies the thread.
When should you wait before buying?
If the manual, machine label, and product listing do not agree, pause and check the manufacturer's model-specific guidance. Do not force a bobbin into the case or adjust the case to make an uncertain size fit.
For Brother model-specific hoop and accessory notes, use the Brother machine lookup and supply notes. To compare the SE700, PE900, SE2000, and Skitch PP1 by field and machine type, see the Brother machine setup comparison.
Common questions about prewound bobbins
Does SA156 fit every Brother machine?
Do not assume so. Brother publishes model-specific accessory guidance. Check the manual or support page for your exact model before ordering.
Are SA156 and SA155 interchangeable?
No. Brother lists different depths for these bobbin parts. Use the part number and type named for your machine.
Does thread weight determine bobbin size?
No. Bobbin format and thread choice are separate. Match the format to the machine first, then follow the machine and design guidance for thread.