My 3 Year Bernette B48 Review (Coverstitch & Serger)

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The Bernette B48 (Amazon link) is a combination serger / coverstitch machine, which means it can sew serger and coverstitch stitches. You just need to convert the machine between each mode. (Note: a serger is called an “overlocker” in the UK and Australia).

I’ve had my B48 for 3 years. I’ve made a huge variety of garments with it, like t-shirts, sweatpants, baby clothes, swimwear, activewear, and dresses. It even assists in my jeans making process!

The B48 is a great way to introduce coverstitches to your sewing projects without needing the space for 3 different machines. It handles a variety of fabrics with ease, and its tension adjustment is very responsive.

However, you should consider how comfortable you are switching back and forth between coverstitch and serger modes. Expect it to take 5 – 7 minutes each time. Although it isn’t difficult, it is something you’ll have to learn, and some people find that it disrupts their sewing flow too much. It also can’t sew top-coverstitches, which is normal for most combo machines. This stitch is desirable for activewear and swimwear enthusiasts. 

You can check the prices on Amazon and Sewing Machines Plus (US).

front view of white bernette b48 coverstitch serger machine
Front view of the Bernette B48 Funlock. Photo credit: Kat Waters.
back view of bernette b48 funlock machine with threads on.
Back view. Photo credit: Kat Waters.

Contents list:

If you want to see what coverstitch and serger (aka. overlocker) stitches look like, we have separate articles with pictures. If you want to see how this machine compares to other combo machines, check out my review of the best serger-coverstitch machines in the UK. And here’s what we recommend if you want a separate serger or coverstitch machine.

Note: My B48 was provided to me by Bernina as part of their ambassador program. As per the contract, my obligations are simply to share projects that I make with the machine on my personal blog (Kat Makes) and social media. I’m not asked to recommend it, and the contract doesn’t extend to sharing outside my own blog or social media. So this partnership has no influence over articles written on Threads Monthly. 

Machine specifications:

  • 2, 3, and 4-thread serger and coverstitches. Plus a 5-thread combo stitch. NO top-cover stitch.
  • Differential feed
  • Manual threading and conversion
  • Color-coded threading paths
  • Serger blade width adjustment
  • LED light
  • NO free arm
  • 8.7cm (3.4″) wide working area
  • 1300 stitches per minute


  • Standard presser foot
  • Cut-offs bin
  • Spare upper knife
  • Dust cover
  • Needle threader tool (it’s not built-in)
  • Screwdriver, allen key, tweezers, and brush.
  • Spool nets and caps

Note: This machine comes with a single presser foot. I recommend getting the foot accessory pack, or the clear sole presser foot, which I personally find makes coverstitching a lot easier!

bernette b48 opened, and accessories.
Front view of the Bernette B48 with the loopers exposed, and the accessories. Photo credit: Kat Waters.

Overall pros and cons:


  • Good performance on a wide range of fabrics
  • Easy to adjust to get tension right
  • The manual has helpful stitch guides and tension suggestions
  • Easy to thread, well lit, and fast


  • Manual conversion from coverstitch to serger takes time to learn
  • Needs extra attention over thick areas like seams when coverstitching
  • Isn’t compatible with generic accessories like binding attachments

Does it sew different fabrics well?

Overall, the B48 sews a wide variety of fabrics with no issues. However, you may have to make adjustments when using specialty threads like wooly nylon or sewing thick fabrics. The manual is very clear and suggests settings. It offers a guide to tension adjustments if your stitches show different “symptoms”, making it easier to get good results.

Swimwear lycra

This swatch is made from matte finish swimwear fabric. The double coverstitch stretches with the fabric, isn’t constricting, and isn’t difficult for the machine to sew at all. Do keep in mind that it’s incredibly important to use ballpoint needles when coverstitching any kind of knit, as universal needles will rip the fabric and stretching will make this worse! Early on, I also had some issues with skipped stitches on a pair of leggings but all I needed to do was swap out my needles. The B48 has no issues sewing this fabric.

purple swimwear lycra with a coverstitched hem.
Swimwear lycra. Photo credit: Kat Waters.

Lightweight drapey jersey

The photo shows the hem of a summer dress I made from a very lightweight merino/tencel blend jersey. I did have to adjust the tension slightly from the defaults suggested by the manual to prevent tunneling, but once this was done the machine had no issues. There’s a guide for these kinds of adjustments in the manual as well.

grey drapey jersey with a grey coverstitched hem.
Lightweight and drapey merino-tencel jersey. Photo credit: Kat Waters.

Medium weight stable cotton jersey

The photo shows the hem of a red t-shirt with flying machines on it – one of the first projects I ever made on the B48, and a great fabric for beginners. I used the default tension settings and had no issues with stitch quality. Plus it’s now held up to 3 years of wear! The machine had no issues sewing this fabric.

coverstitch hem on a printed red tshirt
Medium weight cotton jersey. Photo credit: Kat Waters.

Heavyweight knit

This is the hem of a pair of ponte lounge pants I made. The fabric is quite thick and bouncy, and initially I had some problems with skipped stitches. I used wooly nylon in the looper thread which gives a great effect, but required some tension adjustments to reduce tunneling. This was due to the stretchiness of the wooly nylon. When working with thicker fabrics, the machine can sometimes have issues feeding through areas with bulky seams. I’ve found that using a hump jumper and reducing the presser foot pressure can help prevent this.

coverstitch hem on thick purple fabric
Thick knit fabric. Photo credit: Kat Waters.

Stretch denim

Sewing with stretch denim was a fun bonus of getting this machine! This sample shows a single-fold double stitched hem (similar to the other samples shown) as well as a double-fold single stitched hem, which is more similar to the way jeans are usually hemmed. The bonus of hemming stretch denim with a chain stitch like this is that the hem can stretch along with the fabric (unlike a regular straight stitch) so it’s more secure and less likely to pop.

coverstitched denim hem with pink, white, and orange thread.
Denim hem. Photo credit: Kat Waters.

I used the default tension settings for this sample and reduced the presser foot pressure when I arrived at the bulky seam in the fabric. This helps keep the stitches even. The machine doesn’t have any issues power-wise sewing through multiple layers of denim, but I did hand-turn the stitches over the double-fold hem sample (the area with six layers of denim in the seam!) to keep it even.

I like to use a hump-jumper when the machine is coming down off the bulky area, as the bulk sometimes catches in the back of the foot and decreases the stitch length, but this is definitely avoidable.

Dressmaking cotton

This fabric sews well at the default settings, and the machine has no issues.

This sample shows a double coverstitch on plain weave cotton. I’ll confess that this isn’t a fabric I would normally hem this way. I’d most likely go for a regular straight stitch hem or a blind hem on my sewing machine.

purple cotton fabric with coverstitch hem
Woven cotton fabric (non-stretch). Photo credit: Kat Waters.

However, I caught up with a friend who was wearing a dress she’d made with a similar fabric that she’d chosen to coverstitch. I asked her why. The fabric doesn’t need to stretch, so the coverstitch didn’t seem to add a functional benefit.

These were her reasons. First, time. My friend’s dress had a full gathered skirt and she said the whole hem took her three minutes to complete. (She didn’t press her hem up first, which I don’t recommend, but also it did work!). Second, the effect. She used a triple-coverstitch with some pink contrasting thread that picked up some of the accent colors in her dress. To get three lines of stitching on a regular sewing machine, she’d have had to go around three times.

Topstitching elastic to jersey

This is a closeup of a bralette with thick plush elastic. I topstitched the bralette to the elastic with an adjusted differential feed so that the bralette would gather onto the elastic. The elastic is so plush that you can hardly see the lines of stitching. I love the flat effect this gives – no bulky turned seams. However, it’s really hard to line everything up, so you often end up with bits of fabric poking out on the wrong side.

The settings for this piece took some fussing. The bralette is lined so it was two layers of fabric plus the elastic, plus the adjusted differential feed. Once the tension settings were adjusted correctly, stitching was straightforward with no issues – just don’t stitch over any pins!

purple elastic coverstitched to jersey fabric.
Sewing elastic on jersey. Photo credit: Kat Waters.

Are the stitches good?

Overall, the B48 produces a great stitch quality. In serger mode, this machine has sewn through everything I’ve asked it to without complaint – it’s a workhorse! I find it can handle thicker fabrics than my previous serger, and while the noise changes slightly when it stitches through particularly thick things, it doesn’t affect the stitching at all.

In coverstitch mode, the stitch quality is great as-is when sewing flat areas, but stitching over bulky, uneven areas does sometimes cause problems. You can achieve an even result by:

  • using a hump jumper both leading up to and away from the bulky area,
  • by reducing the presser foot pressure,
  • and (in extreme cases) by hand cranking the machine to form stitches. I’ve only ever done this on extremely thick multi-layered seams.

I’ve heard this feedback about a variety of coverstitch machines at different price points, so it’s not unique to the B48.

Is the B48 good for swimwear?

The B48 is good at sewing a wide range of fabrics, including swimwear material (see my sample above). I’ve happily sewn many pieces of swimwear on my B48, but there are two things to keep in mind if you’re a swimwear enthusiast.

First, the range of accessories is limited, specifically if you want to self-bind things like leg holes or neckbands. There’s a “Binding Foot” accessory that can be purchased separately which I found worked in most cases. However, it struggled with fabrics that were less likely to hold a crease, as your binding needs to be ironed into quarters before it’s fed into this foot. The other option is the more traditional “Coverstitch Tape Binder”.

While other brands can fit universal tape binder attachments, the Bernette range does not, so you’re limited to Bernina models which cost more. Overall, while it’s possible to produce a high quality self-bound hem on this machine, it’s not the easiest option available. This is something to keep in mind if that’s a key priority for you.

Second, the B48 doesn’t offer a top-cover stitch option. This stitch is often used in swim and activewear as a reinforcing stitch. It also adds a decorative layer of stable topstitching to stretchy garments. While you can replicate the top-cover stitch by stitching a three-needle coverstitch upside down, if you’re an avid activewear sewist you may prefer a machine that has a top-cover option. Here’s what I recommend if you want a combo machine or a dedicated coverstitch machine.

Is the B48 good for lingerie?

The B48 stitches delicate fabrics well and I’ve never had issues with fabric being sucked down into the machine, which can happen with lighter weight fabrics. In addition to that, the most valuable features I’ve found for sewing lingerie are the differential feed and adjustable presser foot pressure options.

These features make sewing lightweight, delicate fabrics and laces much easier. They make gathering fabric onto elastic evenly a breeze. And they reduce the number of steps required to finish lingerie projects. However, almost all serger/coverstitch combo machines have these features, so while I do rate this machine highly for lingerie sewing projects, I don’t think this is unique to the B48.

Also, depending on the type of lingerie you’re sewing, the limited range of binding attachments may be a concern for you. Scroll up to the swimwear section to learn more about this.

Is the B48 noisy?

In comparison to other sewing machines I’ve used, it’s noisier. I think part of this is not the volume itself, but the nature of the noise. It has more of a mid-pitched whirr, rather than a low grumble that I’ve heard from some sergers. 

I measured how loud the B48 was at slow, medium, and high speeds. I used a sound level meter app.

SpeedNoise level (db)
Slowest speed66
Medium speed72
Highest speed78

For context, the noise level in my room was 36 db on average before I started the test.

Is the B48 easy to thread?

The front opens fully to allow you to thread the loopers, and it includes several guides and levers that make the process easier. The threading paths are clearly color-coded and it’s fairly straightforward to thread. The machine also comes with a small tool that is both a needle holder (for swapping the needles between their serger and coverstitch positions) and a needle threader. 

bernette b48 front view on white table
Color-coding at the front. Photo credit: Sara Maker.
front view of b48 opened up to see the loopers.
The front opened up so the loopers can be threaded. Photo credit: Kat Waters.

The trickiest part is getting the threads together at the end of a re-threading session. This is a common issue with combo machines. The provided tweezers are a bit too big for the job! I ended up purchasing a pair of angled “detail” tweezers to help with this. They’ve been absolutely incredible for threading, and I use them all the time for picking stray threads, grabbing small items, and snagging tiny things in hard-to-reach places. 

Is the B48 easy to use?

The dials are simple, which means setting the stitch length, tension, differential feed, and cutting width are very easy. And I find that the dials are laid out in an intuitive and easy-to-reach way for me, although this is very much personal preference.

The manual has an awesome threading guide to help you learn which threads go where. There’s also a stitch table that helps you select stitches and tension settings for different fabrics.

The LED lighting is bright. I was particularly impressed with this when I received the machine, as my previous one had an old filament bulb that was quite dim.

The machine does lack a few features that some sewists can’t live without. It doesn’t have a free arm, so you’ll have to change the way you sew small openings like kid’s sleeves or activewear cuffs. The machine opens in the front to give you access for threading, but I’ve had other machines that also have a side opening to make cleaning easier, which the B48 doesn’t have. 

Is switching between serger and coverstitch mode easy or hard?

Here’s the process:

  1. Remove threads from needles and loopers.
  2. Open machine front door, turn the flywheel until the upper looper clutch is aligned with the notch, and flip it backwards into place.
  3. Pull and twist the knife knob to disengage the knife.
  4. Flip the stitch guide switch forward.
  5. Thread the lower looper through the tension discs and following the purple dots. The last step is semi-automatic: after you thread the eye of the looper, use the sliding lever to hook the thread around the looper. 
  6. Remove needles from the serger positions and place them in the coverstitch positions using the provided hex key.
  7. Thread the needles.
  8. Un-snap the serger guard and replace it with the coverstitch guard. 
  9. Adjust the tension for your stitch settings and fabric, and sew!

This looks like a lot when written out, but it’s basically like re-threading your serger from scratch, plus pulling one lever, twisting one knob, and un-snapping one piece to replace it with another.

When I picked up my machine from my local Bernina dealer, I had them walk me through the conversion, and then they watched me as I converted it for the first time. The manual doesn’t do an amazing job of illustrating the conversion (though the threading guides themselves are awesome). However, there’s a good series of videos here that show you exactly what to do. 

I was slow at first while learning, but the conversion now takes me under five minutes to complete, which I think is great when you’re in the middle of a sewing project.

I organize my sewing so that I can do all the serger things first, which means I only have to convert once (to coverstitch mode) to finish the project.

If you think getting 2 separate machines would be easier, keep in mind that you’ll need to buy twice as many cones of thread. That is, unless you plan on removing the ones from your serger to thread your coverstitch. In this case, I suggest you just get the combo machine. It will take the same amount of time to rethread separate machines and combo machines.

There are other combo machines with easier conversion processes, but they come at a higher price point. These machines use air-threading technology to limit the fiddliness of threading. Here are the combo machines with air threading that I recommend.

Is the storage good?

The inside surface of the front door has storage for most of the included accessories. There are a few items that don’t fit, such as the spare knife and the thread spool caps and nets. A small plastic box comes with your machine to store these lesser-used items, and overall I found this to be enough space.

Bernette B42 vs B48

The B42 is a coverstitch-only machine, whereas the B48 is a combination serger-coverstitch machine. This means the B48 can sew coverstitch and serger (also known as overlocker) stitches. The body designs are very similar, they’re both manual threading machines, and both competitively priced.

What to read next…

This article was written by Kat Waters and edited by Sara Maker.

Kat Waters (author)
Kat has been sewing since her feet could reach the pedals, starting with quilts she made with her mom and eventually graduating to garments. She now makes everything she wears, occasionally teaches classes, and shares her projects on social media. Highlights include her wedding dress, shoemaking, and a love for almost any fabric that comes in hot pink! Read more…