What size thread for needle system 16 x 231 (DB x 1) NM 110 Size 18 ?

[MaliMac]

Hi folks! I have recently aquired a brother DB2 B755-3 for sewing some pretty pliable leather. I think I'm using the correct needle size - 16 x 231 (DB x 1) NM 110 Size 18  ... I find sewing machine needle systems a bit mindbending... but I'm concerned the thread I'm using is incorrect and not going to be strong enough with normal wear and tear. I've got Coats Nylbond, in size Tkt 040. it also says Tex 070 but not sure what that means! Any tips? Thanks so much!

[Matt S]

Hi Mac,

Looks like you've got the right class of needle (DBx1) and size thread (TKT40/V69) for your size of needles (Nm110/S18). If you want to go with a thicker/stronger thread you'll have to increase the size of the needle (usually Nm120 for TKT30 thread or Nm140 for TKT20 thread, though you may have to go up or down a size depending on the results in your leather using your machine), still using class DBx1 needles. Of course that assumes that your machine can take heavier threads. I've looked in the manual and there's not much indication of what size range threads it can handle so you might have to experiment, or find other users of the DB2 B755 for information.

Needle and thread sizes are tricky things to get your head around. This chart is pretty handy: https://www.tolindsewmach.com/thread-chart.html
In the UK we tend to talk about TKT sizes e.g. TKT40 (which might also be called M40, 40s or even just "size 40") for thread. In the US the V system is used (e.g. V69=TKT40). There's a lot of different thread sizing systems, some only for certain thread materials. 

These days we tend to use metric needle size designations, since two of the three main needle manufacturers are European. Nm110, for instance, is 1.1mm diameter at the eye of the needle. The old number sizes (e.g. 18) is Singer's sizing system.

As to thread strength that's a little difficult to advise about usefully without knowing what you're sewing  TKT40 nylon has a breaking strain of around 11lb, for what it's worth, it's stronger than it looks.