About the mason jar funnels

Fit your jar first

Choose Regular (70 mm) or Wide (86 mm) mouth, or set a Custom thread diameter, pitch and turns. Print the fit ring preset before the full funnel: it is the same threaded collar, without the cone, so it prints fast. Screw it onto a real jar and adjust Thread clearance until it starts easily and holds without wobbling, then print the full funnel with the same settings.

Shape the funnel

Set the top opening, cone height, outlet size and outlet length for dry goods, liquids or preserves. Vent channels are small holes near the top of the outlet that let air escape while pouring, so liquid doesn’t glug — turn them off for a smoother pour with thicker ingredients. The collar and funnel are one printable piece.

What this is not

The nominal 70 mm and 86 mm mouth sizes are common across many jar brands, but real thread profiles vary between manufacturers, and this generator has not been verified against a real jar — always test the fit ring first. The thread makes the funnel screw-tight, not sealed: it is not airtight and is not guaranteed to hold liquids without leaking around the collar. It is not intended for canning or pressure processing, and food safety is not guaranteed — wash before use.

FAQ

Will this fit my jar? Regular and wide Mason jar mouths (70 mm and 86 mm finishes) are common across many brands, but thread profiles vary between manufacturers and this generator has not been tested against a specific real jar. Print the fit ring preset first and tune Thread clearance against your own jar before printing the full funnel.

Is it airtight or food-safe? No. The thread makes the funnel screw-tight, not sealed — it is not airtight and may leak around the collar. It is not intended for canning, pressure processing, or any use where an airtight or food-safe seal is required. Wash before use.

Why do I need to print the fit ring first? It is the same threaded collar the full funnel uses, without the cone, so it prints in a fraction of the time. Screwing it onto a real jar first means you tune Thread clearance once, cheaply, instead of wasting filament on a full funnel that doesn’t fit.

What do the vent channels do? Small air vents near the top of the outlet tube let air escape while liquid pours, so it flows smoothly instead of glugging. They sit well clear of the threaded collar and don’t weaken it. Turn them off if you’d rather have a smooth outlet wall.

Can I edit it in CAD? Yes: the STEP button gives an exact model with a true helical thread, for both the full funnel and the fit ring.