Which Bag Stitcher Is Right for You?

Choosing the right bagstitcher can be tricky, especially when they all look pretty much the same! Three of the most popular handheld bag closing machines on the market, and the ones we have selected to supply based on years of experience, are the Krafft KF-6, the Siruba AA6, and the Newlong NP-7A.

Each of these machines are tried, tested, and up for the job, but there are a few differences between them that are worth considering before deciding which to invest in. In this blog we break down the key features of each model to help simplify the process.

First up, we’ll look at their similarities:

All these models are:

• Portable, handheld bag stitchers
• Designed for use on paper, woven fabrics, and jute sacks (AKA gunny bags)
• Used to produce a classic single-needle, single-thread chainstitch
• Widely used in agriculture, food, animal feed, recycling, and bulk materials
• 1 needle, 1 thread, 90W engine power. 

Now to discuss the key differences:

Speed 

The Krafft KF-6 comes in at the slowest of the group at a speed of 1,250 stitches per minute. It is still more than capable of keeping up with demand for most small to medium production lines.

The Siruba AA6 is 450spm faster with a top speed of up to 1,700 stitches per minute, falling in-between the Krafft and the Newlong.

The Newlong NP-7A is one of the fastest portable bagstitchers on the market and can be operated at speeds of up to 1,900 stitches per minute. It is well suited to higher-volume production environments where efficiency is critical.

Weight

The Newlong NP-7A is the heaviest and most robust machine. It weighs in at around 6kg.

The Krafft KF-6 weighss in at around 5.9kg. It’s not as lightweight as the Siruba, but marginally lighter than the Newlong.

The Siruba AA6 is often chosen for its lightweight feel, making it ideal for operators working long shifts. It weighs in at around 5.5kg.

*Please note that these weights are approximate as the exact working weight will vary depending on factors such as the thread used.

Max. thickness of the bag being sewn

The Newlong NP-7A and Siruba AA6 can both be used on a maximum bag thickness of 8mm.

The Krafft KF-6 can be used on bags up to 10mm thick.

Stitch length

Although tension can be adjusted, the stitch length on a bagstitcher cannot be altered in the same way as a standard sewing machine.

The Krafft KF-6 has the smallest stitches, with a maximum stitch length of 6.5mm.

The Siruba AA6 is in the middle again, with a maximum stitch length of 7.2mm.

The Newlong NP-7A uses the larges stitches, with a maximum stitch length of 8.5mm.

There isn’t a big difference between them, but users often have a preference. A larger stitch length can provide a faster and more flexible seal, but the smaller length is ideal for securely sealing bags containing fine powders.

Oiling system

Whichever bagstitcher you use, keeping it well-oiled is essential. This is especially important when sewing in close proximity to absorbent powders such as flour.

The Krafft KF-6 uses a manual oiling system, meaning the operator must periodically apply oil to lubrication points on the machine. This has the advantage of mechanical simplicity and easy maintenance, but it relies on regular operator attention.

The Siruba AA6 features an automatic pump oil system that distributes oil from a reservoir to key moving parts while the machine runs. This provides more consistent lubrication and reduces maintenance compared with manual systems.

The Newlong NP-7A uses a built-in oil pump lubrication system that actively circulates oil through internal lines to critical components. This ensures reliable lubrication during continuous high-speed operation and extends machine life, though it still requires periodic monitoring of the oil reservoir and pump system.

And Finally...Price!

The Krafft KF-6 is the cheapest option, retailing at £240 +VAT

The Siruba AA6 retails at £276.25 +VAT

The Newlong NP-7A is the highest priced option, with a retail price of £480 +VAT

(Prices accurate as of 10.03.2026)

So where does each machine win?

Krafft KF-6 – Best Value & Versatility

Advantages:

• Most affordable option
• Handles the thickest bags (up to 10mm)
• Shortest stitch length (6.5mm) to provide a tighter seal
  

Best suited for:

• Small to medium businesses
  
• Companies sealing paper sacks or fine powders
• Users who want a reliable machine at the lowest investment

The KF-6 is ideal if you need a practical, cost-effective bag stitcher that can handle heavier materials while keeping running costs down.

Siruba AA6 – Balanced & Operator-Friendly

Advantages:

• Lightweight (approx. 5.5kg) making it comfortable for long shifts
  
• Well-balanced 7.2mm stitch length
• Excellent value for performance

Best suited for:

• Medium-volume production
• Workshops prioritising operator comfort
• Businesses wanting a balance between cost and speed
  

The AA6 is the “sweet spot” machine, as it is reliable, efficient, and easy to work with day-to-day.

Newlong NP-7A – Premium & High-Performance

Advantages:

• Fastest of the three (up to 1,900 spm)
• Largest stitch length (8.5mm) for fast, flexible closures
• Strong, robust build quality with an established reputation
  
• Advanced lubrication system to increase machine longevity

Best suited for:

• High-output production lines
• Larger manufacturers
• Businesses where uptime and durability are critical
  

The NP-7A is built for performance and long-term reliability in demanding environments.

Conclusion

Choosing the right bagstitcher ultimately comes down to your production volume, bag material, and budget, as well as brand preference.

• If you want the most cost-effective solution with strong sealing performance, the Krafft KF-6 is a smart choice.
• If you’re looking for a balanced, operator-friendly machine that handles most applications comfortably, the Siruba AA6 is hard to beat.
• If speed, durability, and premium build quality are your priority, the Newlong NP-7A is the top dog.

The good news? All three machines are proven, reliable bag closing solutions. The right one for you depends on how and where you’ll be using it.

If you’re still unsure, our team is always happy to advise based on your specific product and production setup.