Tandon Gems

Check mm tolerance on Jaipur-cut rondelles and heishi

Anish Tandon, Founder, Tandon GemsPublished June 10, 2025· Reviewed September 5, 2026· 3 min read

This article is a reference guide. Confirm the current strand, price and quantity with Anish before ordering.

Short answer

Use a digital caliper to spot check diameter on heishi and both diameter and height on rondelles. Measure beads spaced from end to end, note the smallest and largest readings, and compare against the strand's stated size. Accept strands that stay inside the labeled range and read visually even; reject obvious outliers, off-center drilling, or a wobbly silhouette.

In short

  • Measure diameter on heishi, diameter and height on rondelles.
  • Sample across the strand, compare min and max to the stated size.
  • Pass if readings stay in the labeled band and the line looks even.
  • Fail for off-center holes, tilted discs, or visible step-ups.
  • Smaller beads demand tighter visual uniformity than larger beads.

How do I check size tolerance at the table?

Zero the caliper. Measure heishi by outside diameter, and rondelles by diameter and height. Sample beads from both ends, a few along the run, and the center. Write the smallest and largest numbers, then compare to the size on the tag or listing.

Rondelles read two ways. Size is written as diameter by height, for example 4x3 mm on our rondelle shape page. Heishi are measured by diameter only, as shown on the heishi shape page. If the readings stay inside the labeled band and the strand looks even to the eye, it passes.

What variances are acceptable by size range?

Use the listing's stated size as the band. Micro strands in the 2 to 4 mm class should read very even under the caliper, with only slight drift bead to bead. In the 6 to 10 mm class, a gentle center graduation is fine if it is intentional and balanced, but abrupt step ups or random jumps fail.

Across all sizes, outliers that pop out to the eye, off-center holes, or beads that rock when pinched between caliper jaws are rejects. Graded strands should progress smoothly toward the center and back, never in sudden plateaus. Random jumps fail.

How do I check symmetry on rondelles?

Measure diameter, then flip the bead and measure height at a few points to sense wobble. Compare a handful side by side for matching height, since rondelles read as a band of equal thickness. Height sets the line. A good strand keeps height consistent enough that the silhouette looks level when strung.

Centered holes only. Look for drilling through the short axis and even faceting. If one shoulder is taller or the hole drifts, the bead will sit crooked and the strand will snake, which is a fail.

How do I check symmetry on heishi?

Heishi should stack into a clean column. Pinch a small stack with the flat jaws and watch the edges. If discs tilt or the hole is off center, the line breaks. That fails.

Diameter readings should cluster inside the stated size. If the visual read is lumpy or you can spot saucer shaped pieces interrupting the column, keep looking. Trust your eye.

How many 6 mm beads do you need?

Counts keep you honest. Use these working counts to plan and to sanity check a strand's usefulness before you buy. They also help you spot if a strand is too short for your layout.

For a 7.5 in bracelet with a clasp, you bead about 6 in, which is about 25 beads of 6 mm. A 7 in bracelet is about 23. An 18 in necklace is about 70, and a 16 in choker is about 61 of 6 mm.

On a 15 to 16 inch strand of 6 mm rondelles you'll see about 65 to 70 beads. For 8 mm rondelles on a 15 to 16 inch strand, expect about 48 to 52 beads.

What else should we look for before we buy?

Clean holes matter. Check the drill holes for edge chips and burrs, especially on feldspars and quartzes. Inspect the string path for consistent centering so the strand will hang straight. A smooth visual grade is a design asset, a choppy one is time consuming to sort.

If you're matching to a project palette, micro rondelles in sapphire and tourmaline are reliable color builders. Our sapphire guide and tourmaline guide outline the cuts we import from Jaipur, including rondelle and heishi options.

Common questions

What does 4x3 mm mean on a rondelle tag?

It lists diameter by height. A 4x3 mm rondelle measures about 4 mm across and 3 mm tall. Measure both with a caliper to confirm it matches the stated size.

How many beads are on a 15 to 16 inch 6 mm rondelle strand?

About 65 to 70 beads. That's a typical count for a 15 to 16 inch strand of 6 mm rondelles from Jaipur cutters.

Should I knot rondelles or heishi?

You can. Knotting adds about 1 mm per knot and gives more drape. For very small rondelles or tight heishi columns, some makers skip every bead and knot at intervals.

How many 8 mm beads do I need for a bracelet and necklace?

A 7 in stretch bracelet uses about 22 beads of 8 mm. An 18 in necklace uses about 52. For a 16 in choker, plan about 46 of 8 mm.

Sources and checks

  1. How Are Calipers Used in Jewelry Making? - International Gem Society
  2. Standard Gem Sizes Chart: Guide to Gemstone Dimensions - International Gem Society
  3. Melee Sizes for Better Layouts - Ganoksin Jewelry Making Community
  4. To knot beads, or not to knot beads? - Jewelry Discussion - Ganoksin Orchid Jewelry Forum Community for Jewelers and Met

Catalog details are reference information. Ask Anish to confirm the current strand, price and availability.

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