Sewing Machine Bobbin Case: Which One Fits and When to Replace It

First: drop-in or front-loading?

Your manual tells you which system you have. SINGER’s spare case, for example, is made for “Class 15 front-loading systems” only.¹ On Brother’s SE700, the bobbin goes in from the top under a bobbin cover, and the case sits under the needle plate cover; the manual has you take it out to clean the race and put it back “so that the mark on the bobbin case aligns with the mark on the machine”.²

SINGER adds that its Class 15 bobbins fit “the majority of SINGER front-loading and top drop-in bobbin sewing machines”, and that plastic bobbins “won’t damage top drop-in bobbin cases”.⁸

When to replace it

Signs that the bobbin case needs replacing, per the makers

What you see	What the maker says
Scratches or a burr on the case	Brother: never use it, “Otherwise the upper thread may become tangled, the needle may break and cause injury.”2
The bobbin thread keeps breaking	JUKI lists “The rubbing of the bobbin case spring has produced a slot” and says to replace the case.4
The case sits wrongly	Brother: “Be sure that the bobbin case is correctly installed, otherwise the needle may break and cause injury.”2

Brother’s manual lists no part to order: “For a new bobbin case, contact your nearest Brother authorized service center.”² JUKI sends TL owners to its dealers.⁴

Remove and clean it

Brother explains why: “Stitching performance will suffer if lint and dust collects in the bobbin case, therefore, it should be cleaned regularly.”² The SE700 steps, in short: raise the needle, turn the machine off and unplug it, remove the needle, presser foot, bobbin cover and needle plate cover, then “Grasp the bobbin case, and then pull it out.” Brush the race, then put the case back with the two marks aligned.² No oil: “Do not apply oil to the bobbin case.”²

Brother embroidery machines: two cases

Some Brother embroidery machines ship with two bobbin cases; the XP3’s accessory list names a standard case “(green marking on the screw) (on machine)” and an “Alternate bobbin case (no color on the screw)”.⁵

• Green screw: leave it alone. Brother: “Do not adjust the tension screw on this bobbin case with the green marked screw.” It recommends the included embroidery bobbin thread with it.⁶
• No colour on the screw: tighter, adjustable. It “is set with tighter tension for embroidery with different weights of bobbin threads”, and has “a dark colored mark on the inside of the bobbin cavity”.⁶ To adjust it, take the bobbin out first, turn only the slotted (-) screw, about 30 to 45 degrees at a time, and “Do not turn a phillips screw (+).”⁷

Janome: colour dots

Janome Australia explains: “The majority of Janome Bobbin Holders have a coloured dot, the most common being the red dot bobbin holder for everyday sewing.” The blue dot holder for free-motion quilting is “preset with a lower tension”.⁹

Five bobbin cases and where to get them

For front-loading SINGER machines

SINGER Bobbin Case, Class 15

System

Class 15, front-loading

Bobbins

SINGER Class 15 only

Tension

adjustable screw

Strengths

• Sold on SINGER’s US and Canadian stores
• SINGER says it handles thicker threads with its adjustable screw

Drawbacks

• No model list on the page: check your manual first

Good fit: you own a front-loading Class 15 SINGER and want a spare case, or a second one for bobbin work.
Skip it if: your machine is drop-in (top-loading): this case is for front-loading systems.

Tighter, adjustable case for embroidery

Brother alternate bobbin case (no colour on the screw)

Identification

no colour on the screw, dark mark inside

Tension

tighter; slotted screw adjustable

Part number

not published by Brother in the documents read

Strengths

• Brother explains when and how to adjust it

Drawbacks

• No part number or product page found

Good fit: your Brother embroidery machine came with it and you use another bobbin thread.
Skip it if: you sew everyday seams: Brother points to the green-screw case.

A separate case for bobbin work

Brother SABWRK1 Bobbin Work Kit

Contents

bobbin case for Bobbin Work, specialty bobbin cover, screwdriver, CD-ROM, 20 design templates

Canada

SABWRK1C

Strengths

• Compatible-model list on Brother’s page (SE400, SE600, PE500, NX400 and others)
• Sold by Brother USA and Brother Canada

Drawbacks

• Instructions on CD-ROM

Good fit: you own a Brother Innov-ís model on its list and want to sew thick threads or ribbons from the bobbin.
Skip it if: you only need a standard replacement case.

Lower tension for free-motion quilting

Janome Blue Dot bobbin holder

Part 200445007

top-loading models with built-in thread cutter (9 mm and 7 mm), except Continental

Part 202006008

top-loading 7 mm models without thread cutter

Part 202433008

Continental CM17, CM8P, CM7P, CM6

Strengths

• Part number per machine group in Janome’s sheet

Drawbacks

• Australian document: North American part numbers not confirmed
• Sold through dealers

Good fit: you free-motion quilt on a top-loading Janome.
Skip it if: you sew everyday seams: Janome’s red dot holder is the everyday one.

Exclusive JUKI part

JUKI TL series bobbin case

Fits

JUKI TL series (TL-90 family)

Where

JUKI dealers

Part number

not given in the manual

Strengths

• JUKI’s manual gives a simple bobbin tension test

Drawbacks

• No part number in the manual

Good fit: your TL’s bobbin thread keeps breaking and the case spring is worn.
Skip it if: you own another machine: JUKI calls it an exclusive part.

JUKI’s test for a TL case: hold the bobbin thread and shake it; the case should go down slowly (with #50 thread).⁴ SINGER’s case is listed on its Canadian store, and Brother Canada sells the bobbin work kit as SABWRK1C.^10,11 The SABWRK1 kit is “Compatible with most Brother Innov-ís Sewing and Embroidery Machines”.¹²