Bath Bomb Mold Size Chart: A-I Cavities vs Press, Not Guessed Ounces

You searched bath bomb mold sizes because a listing promised 5 oz and your press made a 3.2 oz puck that crumbles. Ounce is a packed-density number. Cavity OD and depth are the mold numbers. We will not invent a universal oz chart and put RUUIPON's name on it.

RUUIPON quotes custom bath-bomb cavities in Shenzhen since 2018. MOQ 20 trays per design. Quote ~24h on a measurable RFQ. Prototype commonly 3-7 business days after CAD lock. Drawing deposit ~$50 USD when we must model cavities. Use-path is cosmetic / bath, not food-contact, unless you separately quote an edible SKU.

Why a Public Ounce Table Lies

Two shops pack the same 70 mm well to different grams because citric ratio, oil, and dwell time change density. A blog that lists "Size C = 4.5 oz" is marketing, not tooling. If a competitor published ounces without naming mix and press, treat it as unverified. We keep ounces off the canonical chart unless you send weighed pucks from your line.

A-I Cavity Chart We Actually Quote Against

Letters below are cavity OD bands we use in RFQs, not a claim that every factory on the internet uses the same letter. Confirm your press die OD with a caliper. Depth is a second number; a shallow 70 mm well is not a deep 70 mm well.

Letter (RFQ)	Typical cavity OD band	What we ask next
A-B	About 30-45 mm	Guest amenity / petit bomb. Wall vs crumbling edge.
C-D	About 50-55 mm	Common retail start. Confirm press cup ID.
E-F	About 60-65 mm	Retail "large" photos. Depth drives pack height.
G-H	About 70-80 mm	Heavier puck. Call oil load; stick rises.
I	About 85 mm+	Statement puck. Shipping crush and demold flex both get worse.

Depth, hemisphere vs flat-back, and whether you press two halves are not in the letter. A two-half bomb is two cavities or a clamshell, not "size E twice." Existing use article: silicone mold for bath bombs. Truffle press is a different density job: bath truffle press.

Press Stroke vs Cavity OD

If your hand press cup is 64 mm ID and you order a 70 mm cavity, you will flash powder and blame Shore. We match cavity OD to the hardware you already bought, or we tell you to change hardware. Shore too soft ovals the equator; Shore too hard can mark a brittle mix. We set Shore after you name press vs pour.

Send This Instead of a Pinterest Size

Caliper OD of the puck you like, or the press cup ID. Target packed grams if you have a scale. Hemisphere or bar. Logo yes/no and depth guess in mm. Weekly pieces. Ship-to country. Form: custom silicone mold quote or contact. WhatsApp +86 135 3006 2969.

FAQ

What is the HS-adjacent size for bath bombs?
There is no customs size. There is cavity OD and packed grams. Do not put ounces on an invoice as if they were tooling dimensions.

Can you copy a retail size C mold I bought?
No. We tool from your files or a master you own. Letters are not a license to clone a brand cavity.

MOQ?
20 trays per design.

Quote: contact.