Frequently Asked Questions about Bead Hole Sizes

10mm round beads and their holes, which range from 1.1 - 1.9 mm

At BeadShopUK one of the most common questions we get asked is regarding the size of the holes on our beads, so we put together this helpful FAQ to help you understand some of the problems you may encounter when working with semi-precious, gemstone and freshwater pearl beads.

What sizes are the holes on your beads?

Unfortunately there is no simple answer.  In general, bead hole sizes can range from 0.5mm on a 4mm round bead to a 1mm hole on a 10mm round bead, but they can get up to 1.5mm.

Why do beading holes vary in size?

It’s all to do with the extensive range of semi-precious stone beads and how the material varies in its hardness. As a general rule, the harder the stone the smaller the beading hole will be. This applies even on large stones.   

Why are freshwater pearl beads holes so small?

The hole sizes of freshwater pearls beads are much smaller compared to stone beads. Their hole sizes typically range from 0.5 – 0.6 mm. Traditionally pearls were threaded using knotted silk which may explain the small holes.

Why are the hole sizes important? 

The main reason beaders need to know the beading hole size is to match with their stringing material – with the increased use of cord, rattail, leather and elastic being used in designs a larger beading hole is required. 

Holes on pearls can be quite small

Secondly, for security of your chosen design, the correct gauge beading thread should be used. For example if you are using a large hole bead on fine thread there will be a lot of movement which could cause abrasion and breakage.  The most desirable combination is to use the largest diameter thread that will pass through the smallest bead hole in your design.  For this you need to know the size of the beading hole.

How do you measure the size of the bead holes?  

You do not need expensive tools or callipers to find this out. We measure holes with a range of calibrated drill bits. You can actually buy them in sets for use with a Dremel. They range from 0.3 mm to 2 mm in width. You can insert these drill bits into the bead hole and measure its size. Easy.

How can I enlarge the size of my beading holes? 

Most professional beaders have a Bead Reamer in their armoury of tools.  This handy tool has a selection of diamond coated tips which allows you to grind yourself a bigger hole. A Bead Reamer works really well for enlarging holes and for smoothing the edges of holes in gemstone and glass beads.

A good trick to remember is to use your reamer under water. Not only does this prolong the life of the diamond coasting but it also removes the risk of you inhaling any dust. Don’t force the reamer, but take your time and work slowly from one side of the bead and then the other. If you are too heavy handed you risk chipping the bead or even breaking it into two.

Example of hole sizes on Carnelian round beads

When we make our Worry Beads, we have to enlarge the hole sizes of our 10mm beads to 2mm as they need to be very loose on a strong cord.  To do this by hand would take too long, so we use our diamond bits with an electric pendant drill.  We use the same technique as for the hand reamer but much more care is required (water and electricity don’t mix!) and we always wear safety glasses.

How do I enlarge the hole size of my freshwater pearl beads?

If you wish to enlarge the holes of pearls, then the best tool to use is a pearl reamer – similar to the bead reamer but built specifically for pearls.  It has a fine corkscrew like tip which is much finer.  This is used “dry” (unlike the bead reamer).  However, the nacreous dust can be harmful and it would always be recommended that take precautions against inhaling or ingesting this.

We hope you found this helpful, but here are a couple more tips worth thinking about:

•  If the beading hole size is important to your design it is always worth checking with your supplier before purchasing.

•  It’s also worth remembering that hole sizes can vary from each batch of beads, so those beads you ordered last year might have had really big holes compared to the ones you bought a couple of days ago.