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Juki MO-644D

Ranked #5 of 40 in Best Sergers and Coverstitch Machines (2026). Here is every spec we scored, where it came from, and how it compares.

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#5

Juki MO-644D

Best for: 4-thread official maximum, 1,500 official SPM, official differential feed

6.6/10

What we like

  • Official table lists a 4-thread maximum
  • Official table lists a maximum speed of 1,500 SPM
  • Official table lists differential feed

Watch out for

  • Official table we used does not list a stitch width

Score breakdown

Official maximum thread count 30%
Official maximum sewing speed 30%
Official stitch width * 20%
Official differential feed 20%

* Not published by the manufacturer; scored at the lowest published value in this category, so an unpublished figure never outranks a published one.

Official maximum thread count4 threads
Official maximum sewing speed1500 SPM
Official stitch widthNot listed
Official differential feedYes
Official machine weight15 lb
Official dimensions10.6”(W) x 13.5”(H) x 11.5”(D)
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Specs source:

How it compares

Open the full comparison table

Baby Lock Splendor
8.4/10
#1 · 8-thread official maximum, 7.5 mm official stitch width, official differential feed
Baby Lock Triumph
8.4/10
#2 · 8-thread official maximum, 7.5 mm official stitch width, official differential feed
Juki MO-735
7.1/10
#3 · 5-thread official maximum, 1,500 official SPM, official differential feed
Baby Lock Applaud
6.9/10
#4 · 6-thread official maximum, 6 mm official stitch width, official differential feed
Juki MO-654DE
6.6/10
#6 · 4-thread official maximum, 1,500 official SPM, official differential feed
Singer S0600 Serger Machine
6.6/10
#7 · 4-thread official maximum, 1,500 official SPM, official differential feed
Juki MO-1000
6.6/10
#8 · 4-thread official maximum, 1,500 official SPM
Baby Lock Acclaim
6.4/10
#9 · 4-thread official maximum, 7.5 mm official stitch width, official differential feed
Baby Lock Celebrate
6.4/10
#10 · 4-thread official maximum, 7.5 mm official stitch width, official differential feed
Baby Lock Serenity
6.4/10
#11 · 4-thread official maximum, 7.5 mm official stitch width, official differential feed
Baby Lock Victory
6.4/10
#12 · 4-thread official maximum, 7.5 mm official stitch width, official differential feed
Singer Professional 5 14T968DC Serger
6.4/10
#13 · 5-thread official maximum, official differential feed
Brother 1034D
6.2/10
#14 · 4-thread official maximum, 1,300 official SPM, 7 mm official stitch width, official differential feed
Brother 1034DX
6.2/10
#15 · 4-thread official maximum, 1,300 official SPM, 7 mm official stitch width, official differential feed
Brother 1634D
6.2/10
#16 · 4-thread official maximum, 1,300 official SPM, 7 mm official stitch width, official differential feed
Brother 1634DX
6.2/10
#17 · 4-thread official maximum, 1,300 official SPM, 7 mm official stitch width, official differential feed
Brother ST4031HD
6.2/10
#18 · 4-thread official maximum, 1,300 official SPM, 7 mm official stitch width, official differential feed
Baby Lock Vibrant
6.2/10
#19 · 4-thread official maximum, 7 mm official stitch width, official differential feed
Juki MO-623
6.1/10
#20 · 3-thread official maximum, 1,500 official SPM, official differential feed
Husqvarna Viking Amber S 300 Overlock Machine
6.1/10
#21 · 1,500 official SPM, official differential feed
Juki MO-2800
6.1/10
#22 · 1,500 official SPM, official differential feed
Juki MO-655
6.1/10
#23 · 1,500 official SPM, official differential feed
Pfaff admire 3000 Overlock Machine
6.1/10
#24 · 1,500 official SPM, official differential feed
Baby Lock Euphoria
5.9/10
#25 · 4-thread official maximum, 6 mm official stitch width, official differential feed
Brother 1134DW
5.9/10
#26 · 4-thread official maximum, 1,300 official SPM, official differential feed
Brother 3234DT
5.9/10
#27 · 4-thread official maximum, 1,300 official SPM, official differential feed
Brother AIRFLOW3000
5.9/10
#28 · 1,300 official SPM, 7.5 mm official stitch width, official differential feed
Singer 14HD854 Heavy Duty Serger
5.9/10
#29 · 4-thread official maximum, 1,300 official SPM, official differential feed
Singer HD0400S Heavy Duty Serger
5.9/10
#30 · 4-thread official maximum, 1,300 official SPM, official differential feed
Juki MO-104D
5.9/10
#31 · 4-thread official maximum, official differential feed
Juki MO-114D
5.9/10
#32 · 4-thread official maximum, official differential feed
Singer HD0450S Heavy Duty Serger
5.9/10
#33 · 4-thread official maximum, official differential feed
Singer Heavy Duty 0420 Serger with 13 Built‑In Stitches, Heavy Duty Motor & Differential Feed
5.9/10
#34 · 4-thread official maximum, official differential feed
Singer Heavy Duty 0460 Serger with 13 Built‑In Stitches, Easy View Threading & Differential Feed
5.9/10
#35 · 4-thread official maximum, official differential feed
Singer S0080 Serger
5.9/10
#36 · 4-thread official maximum, official differential feed
Brother AIR1800
5.4/10
#37 · 1,300 official SPM, official differential feed
Husqvarna Viking Amber Air S 400 Overlock Machine
5.4/10
#38 · 1,300 official SPM, official differential feed
Husqvarna Viking Amber S 100 Overlock Machine
5.4/10
#39 · 1,300 official SPM, official differential feed
Juki MO-80CB
5.4/10
#40 · 1,300 official SPM, official differential feed