Canning Lid Sizes Explained
Canning lids come in two sizes to match jar mouths: regular-mouth (about 70mm) and wide-mouth (about 86mm). They are not interchangeable. Standard flat lids are single-use for canning; the screw bands are reusable.
Two sizes, matched to the jar
Flat canning lids come in regular-mouth (about 70mm) and wide-mouth (about 86mm). The lid must match the jar mouth, and the two are not interchangeable, so check which mouth your jars have before buying lids.
Flat lid plus band
Modern canning uses a two-piece system: a flat lid with sealing compound, and a screw band that holds it during processing. After the jar seals and cools, you can remove the band for storage.
Single-use lids
Standard flat lids are single-use for canning, because the sealing compound seals once. Use a new flat lid each batch for a safe seal, and reuse the bands. Special reusable lids exist but must be used per their own instructions.
Frequently asked questions
Are regular and wide mouth lids interchangeable?
No. Regular-mouth lids are about 70mm and wide-mouth about 86mm, so they only fit their matching jar. Check your jar mouth before buying lids.
Can you reuse the screw bands?
Yes. The screw bands are reusable as long as they are not rusted or bent. Only the flat sealing lids are single-use for canning.