# Mason jar flat lids: regular Ø70.00 and wide-mouth Ø86.00

> What is the diameter of a mason jar lid?

- Category: Hardware › Found & household materials
- Kind: Standard part
- Basis: Regular 70 mm (2 3/4 in) and wide-mouth 86 mm (3 3/8 in) flat lids; 0.154 mm tinplate (GPI 450 metal closure spec, 0.00605 in minimum nominal)
- Page: https://xemstudio.com/objects/mason-jar-lid/ · JSON: https://xemstudio.com/api/geometry?object=mason-jar-lid · Plain text: https://xemstudio.com/objects/mason-jar-lid/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

**Exact dimensions.** Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part.

## Notes

- Flat lids: regular mouth Ø70.00, wide mouth Ø86.00, both 0.154 mm thick. Each file is a plain disc at those sizes.
- Not drawn, because no dimension is published for it: the sealing-compound ring and the formed (embossed) profile.
- The lid sits on the jar's glass rim inside the band; the regular band's thread root is Ø71.22, so the Ø70.00 lid sits inside it.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| flat lid on jar mouth under the band | Ø70.00 disc in Ø71.22 band thread root | glass rim, clamped by the band | clamp | mason-lid-flat-regular-70* |
| flat lid on jar mouth under the band | Ø86.00 disc | wide-mouth glass rim and band | clamp | mason-lid-flat-wide-86* |

## Sizes

| lid | dia_mm | thickness_mm |
|---|---|---|
| regular mouth | 70.0 | 0.154 |
| wide mouth | 86.0 | 0.154 |

## Where the files are

- Wikipedia: [Mason jar](https://en.wikipedia.org/wiki/Mason_jar) — web — CC BY-SA 4.0 (text)
- Ball (Newell Brands): [Ball canning jars and lids](https://www.ballmasonjars.com/) — web — Ball site (verify at link)
- Comet Tool Co.: [70-450 continuous-thread closure drawing (part 1340-0109): T 2.804 in at skirt, E 2.700 in at midpoint, 4 TPI (.250 pitch), 1 1/4 turns](https://www.comet-tool.com/wp-content/uploads/2021/08/70-450-0109-merged.pdf) — PDF — manufacturer drawing (verify at link)
- WebstaurantStore (Ball 30000): [Ball regular-mouth lids and bands: top diameter 2 3/4 in, height 9/16 in](https://www.webstaurantstore.com/ball-30000-regular-mouth-replacement-lids-and-bands-pack/52730000.html) — web — listing (verify at link)
- WebstaurantStore (Ball 40000ZFP): [Ball wide-mouth lids and bands: top diameter 3 3/8 in, height 5/8 in](https://www.webstaurantstore.com/ball-40000zfp-wide-mouth-lids-and-bands-for-canning-jars-pack/52740000.html) — web — listing (verify at link)
- Healthy Canning: [Lids for home canning: regular mouth 70 mm (2 3/4 in), wide mouth 86 mm (3 3/8 in)](https://www.healthycanning.com/lids-for-home-canning/) — web — site (verify at link)
- The Cary Company: [70G-450 metal lid spec 30WG70 (GPI 450 finish; tinplate minimum nominal thickness .00605 in)](https://www.thecarycompany.com/media/pdf/specs/30WG70.pdf) — PDF — distributor spec (verify at link)
- Long Earth Society: [Engine builds (videos and write-ups)](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (2 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/mason-jar-lid/index.json

- mason-lid-flat-regular-70: [STEP](https://xemstudio.com/files/hardware/mason-jars-and-lids/mason-lid-flat-regular-70.step) · [STL](https://xemstudio.com/files/hardware/mason-jars-and-lids/mason-lid-flat-regular-70.stl) — regular-mouth flat lid: Ø70.00 disc (2 3/4 in), 0.154 mm tinplate; sealing-compound ring and formed profile not drawn (no published dimensions)
- mason-lid-flat-wide-86: [STEP](https://xemstudio.com/files/hardware/mason-jars-and-lids/mason-lid-flat-wide-86.step) · [STL](https://xemstudio.com/files/hardware/mason-jars-and-lids/mason-lid-flat-wide-86.stl) — wide-mouth flat lid: Ø86.00 disc (3 3/8 in), 0.154 mm tinplate; sealing-compound ring and formed profile not drawn (no published dimensions)

## How it fits

### Goes in or on
- [Mason jars: regular (60 mm mouth) and wide-mouth (76 mm mouth), outside envelopes](https://xemstudio.com/objects/mason-jar/): sits on the jar's rim

### Connects to
- [Mason jar screw band, regular mouth (70-450 thread)](https://xemstudio.com/objects/mason-jar-band/): the band clamps it to the rim

## Questions

**What diameter is a regular mouth mason jar lid?**

70.00 mm (2 3/4 in); a wide-mouth lid is 86.00 mm (3 3/8 in). Both are 0.154 mm tinplate.

**How thick is a mason jar lid?**

0.154 mm (0.00605 in) tinplate, the minimum nominal thickness in the 70-450 metal closure spec.

## Fits with

- [Mason jar screw band, regular mouth (70-450 thread)](https://xemstudio.com/objects/mason-jar-band/)
- [Mason jars: regular (60 mm mouth) and wide-mouth (76 mm mouth), outside envelopes](https://xemstudio.com/objects/mason-jar/)
- [Laboratory rubber stoppers #0–#13 (25 mm tall)](https://xemstudio.com/objects/rubber-stoppers/)
- [O-rings, common metric sizes (ISO 3601)](https://xemstudio.com/objects/o-rings-metric/)
- [Steel food cans: soup, vegetable, tuna, #2, #2½, #10, coffee](https://xemstudio.com/objects/steel-food-cans/)