Mandrel Sizes and Types for Beadmaking: Diameters, Hole Sizes, and Care

Short answer: Beadmaking mandrels are stainless steel rods sold in diameters from 1/16 inch up to 1/8 inch, with 1/16, 5/64, 3/32, and 1/8 inch the common sizes — in metric markets, 1.6 mm and 2.4 mm are the mainstays. The mandrel’s diameter (plus a thin layer of bead release) sets your bead’s hole size, so pick by how the bead will be strung: 1/16” (≈1.6 mm) for holes that string straight onto bead wire, 3/32” (≈2.4 mm) as the all-purpose “workhorse,” and 1/8” (≈3.2 mm) for large holes suited to cord and leather. Dip the working end in bead release, let it dry standing upright, and a mandrel can be cleaned, re-dipped, and reused for years.

What a mandrel does (and why hole size starts here)

A mandrel is the steel rod you wind molten glass around to form a bead. The rod itself would fuse to the glass, which is why the working end is coated in bead release — a clay-like slip that stops molten glass from sticking to the metal and is exactly what makes mandrels reusable (Fritipedia). When the bead is cool, you twist it off the mandrel and the release crumbles out of the hole.

That mechanism means hole size is decided before you ever light the torch: the hole is the mandrel diameter plus the thickness of the release coating. Everything else in this article — which diameters to buy, how many, how to care for them — flows from that.

Standard diameters: 1/16”, 3/32”, 1/8” — and metric equivalents

Standard beadmaking mandrels are stainless steel rods sold from 1/16 inch up to 1/8 inch in diameter, with 1/16, 5/64, 3/32, and 1/8 inch the common sizes (Zooziis). In the UK, mandrels are sold in metric sizes, with 1.6 mm and 2.4 mm the main options; 2 mm is common in mainland Europe but scarce in the UK (Fritipedia).

Editor’s note: the metric figures are rounded selling conventions, not exact conversions — 1/16” is 1.5875 mm sold as 1.6 mm, 3/32” is 2.381 mm sold as 2.4 mm, and 1/8” is 3.175 mm sold as 3.2 mm. In practice the imperial and metric versions are interchangeable.

What hole size each mandrel actually gives you

The finished hole comes out slightly larger than the mandrel diameter, because the bead release coating adds thickness. How much larger varies: pulling the mandrel out of the release dip more slowly leaves a thinner coating and a hole closer to the actual mandrel size (Fritipedia). Dip technique and release brand both change the result, so treat the sizes below as guidance rather than a promise of exact dimensions.

• 1/16” (≈1.6 mm) — the thinnest standard mandrel yields a small hole that strings directly on bead wire. The trade-off: it bends most easily and demands good heat control, which makes it the hardest size for beginners (Zooziis).
• 5/64” (≈2 mm) — a hole still usable for stringing on wire or wire-wrapping, with noticeably better bend resistance than 1/16”; it lasts well under typical use (Zooziis).
• 3/32” (≈2.4 mm) — the workhorse and the most popular size. It takes heavy use without bending easily, though its larger hole usually needs a spacer or support to stay centered on bead wire (Zooziis; Fritipedia).
• 1/8” (≈3.2 mm) — hard to bend, and produces a large hole suited to threading on cord, such as leather (Zooziis; Fritipedia).

If you’re starting out, the practical reading is simple: buy mostly 3/32”, add 1/16” or 5/64” once your heat control is steady, and keep a few 1/8” on hand for cord-strung beads.

Stainless steel vs other materials

Stainless steel is the preferred mandrel material, and for good reasons: it withstands beadmaking temperatures without bending, keeps a smooth surface over many beads, and has low heat transfer — so the end you’re holding stays cool while the working end sits in the flame (Gossamer Glass Studio; Zooziis). Improvised rods in other metals give up at least one of those properties, which is why virtually all commercial beadmaking mandrels are stainless. A smooth, unblemished surface also matters for release adhesion and for getting the finished bead off cleanly, so favor proper stainless mandrel stock over scrap rod.

Specialty mandrels: hollow, puffy, and key-ring types

Beyond straight rods, specialty mandrels open up other forms:

• Hollow / “Puffy” mandrels. The Puffy Mandrel is a hollow-tube mandrel for blowing hollow beads — essentially a furnace blowpipe scaled down to bead size. It was originally made by Amnon Elbaz and is now manufactured and sold by artist Jeri Warhaftig; it’s made from medium-wall surgical steel and works for soft glass and even boro (jeriwarhaftig.com). The technique: coil disks together with no air gaps, melt them into a sealed hollow form while covering the open end of the mandrel, then inflate the bead with “a very tiny puff of breath” through the tube.
• Big-hole and shaped mandrels. At the large end of the standard range, 1/8” (and larger specialty stock) produces cord-friendly holes; various vendors also sell shaped and key-ring mandrels for pendants and findings. These follow the same release-and-reuse workflow as straight rods.

For structured learning on techniques like hollow beads, the International Society of Glass Beadmakers maintains non-commercial education resources at isgb.org/education.

Prepping mandrels: dipping and drying

The standard prep workflow is straightforward: dip the working end of the mandrel in bead release, then stand the mandrels vertically to dry — in a purpose-made rack or simply a can of rice. Many beadmakers dip a batch in the evening so a set of dried mandrels is ready for the next session (The Alchemistress; Glass With A Past). Dip speed matters more than it looks: a slower pull leaves a thinner, more even coating and a hole closer to the mandrel’s true size (Fritipedia).

Release choice, air-dry vs flame-dry, and troubleshooting cracked coatings are their own topic — covered in full in our bead release guide.

Cleaning and reusing mandrels

Mandrels are consumables only in the loosest sense — cleaned properly, they cycle through your studio indefinitely. The routine from Gossamer Glass Studio’s beginner series:

1. Scrub used mandrels with steel wire or steel wool and soap (gloves on) to remove old release and skin oils.
2. Dry completely before re-dipping — release won’t adhere well to a damp or oily rod.
3. Dispose of release-laden rinse water outside, not down the sink, where the clay sediment can settle in your plumbing (Gossamer Glass Studio).

If a finished bead is stuck, don’t fight it dry: soak the bead and mandrel in water to soften the release, then grip the mandrel with pliers just below the bead and wiggle the mandrel — not the bead — back and forth until it frees (Lampwork Etc.).

Bent mandrels: straighten or retire?

A bent mandrel makes lopsided beads and wobbles in your fingers, so check before you dip: roll each mandrel on a flat table — any bend shows up immediately as a wobble. To straighten one, squeeze it along wide flat-jawed pliers while rotating the rod, or work it in a table vice (Lampwork Etc.).

Be realistic about what’s recoverable, though. Forum consensus is that thin 1/16” mandrels rarely straighten well, and a badly bent mandrel of any size is better retired — mandrels are cheap, and a rod that’s been worked back and forth never rolls quite true again. Straightening is worth a try on the thicker sizes with mild bends; beyond that, bin it and dip a fresh one.

How many mandrels to buy

More than you think, but not vastly more. The bottleneck is drying time: every mandrel you use in a session needs to be cleaned, re-dipped, and dried before it works again, which is why the batch-dip-in-the-evening habit exists. A useful reference point: a typical DIY drying rack holds a couple dozen mandrels at a time — a fair reflection of the working quantity beadmakers keep in rotation (Glass With A Past).

A sensible starter buy: a couple dozen 3/32”, a handful each of 1/16” (or 5/64”) and 1/8”. That covers a full session with spares for the inevitable bent or stuck-bead casualties, and lets one batch dry while another is in use.

Pairing mandrels with the right torch

Mandrels are the cheap half of the beadmaking equation — the torch is the other. Soft-glass beadmaking favors compact, controllable flames, and the classic pairings are torches like the Nortel Minor, the Carlisle Mini CC, and GTT’s small surface-mix burners such as the GTT Cricket and GTT Lynx. Heat control matters directly to your mandrel choice: the thin 1/16” rods that give the daintiest holes are also the ones that punish an overheated, wandering flame.

For the full torch rundown, see best torch for glass beads, and for plumbing it all together, the lampworking torch setup guide and the complete buyer’s guide.

Key takeaways

• Standard mandrels are stainless steel, sold in 1/16, 5/64, 3/32, and 1/8 inch (metric: 1.6 mm, 2.4 mm, 3.2 mm, with 2 mm common in mainland Europe).
• Hole ≈ mandrel diameter + release coating — a slower pull from the dip means a thinner coat and a truer hole, but exact dimensions vary with technique and brand.
• 3/32” (2.4 mm) is the workhorse; 1/16” strings on bead wire but bends easily; 1/8” suits cord and leather.
• Prep: dip in bead release, dry standing upright, batch-dip the night before. Clean: steel wool and soap, dry fully, dump rinse water outside.
• Bent? Roll-test on a flat table; straighten thicker rods with flat pliers or a vice, but retire badly bent and thin bent mandrels — they’re cheap.
• Keep a couple dozen in rotation, and pair them with a controllable soft-glass torch (see the beads torch guide).

Sources

• Zooziis, “Which mandrels can I use?” — https://www.zooziis.com/pages/which-mandrels-can-i-use
• Fritipedia, “Mandrel” — https://www.frit-happens.co.uk/wiki/Mandrel
• Fritipedia, “Bead release” — https://frit-happens.co.uk/wiki/Bead_release
• Jeri Warhaftig, “Puffy Mandrel instructions” — https://www.jeriwarhaftig.com/puffy-mandrel-instructions
• Gossamer Glass Studio, “Beads From the Beginning” — https://gossamerglass.com/2021/11/28/beads-from-the-beginning/
• The Alchemistress, “Studio Set Up Part Five: Bead Release & Mandrels” — https://alchemistressbeads.wordpress.com/2015/08/14/studio-set-up-part-five-bead-release-mandrels/
• Glass With A Past, “DIY Mandrel Drying Rack” — https://glasswithapast.com/knowledgebase/diy-mandrel-drying-rack/
• Lampwork Etc., “Reusing mandrels????” — https://www.lampworketc.com/forums/archive/index.php/t-166999.html

Editor’s note: hole sizes, metric equivalents, and working quantities above are conventions and community practice, not precise specifications — release brand, dip technique, and vendor stock all vary. Follow the instructions from your bead release and specialty-mandrel manufacturers where they differ from anything here.