Classic with Steel Loop Cap
The plain Klean Kanteen Classic bottle paired with the all-stainless Steel Loop Cap - a 100% steel drink environment with no gasket, sealing steel-on-steel.
Plastic-free verdict: Plastic-free
The Classic bottle is 18/8 stainless steel, and the Steel Loop Cap is a single unibody piece of 18/8 stainless - threads included - that seals steel-on-steel with no plastic and no silicone gasket. Klean Kanteen states it creates a "100% stainless environment" so drinks never touch plastic. When you buy the Classic (narrow-mouth, internal-thread) body together with this cap, nothing in the water path is plastic or silicone, which is genuinely rare in this category. Applies to the adult Classic and the Kid Classic body, both of which take the narrow-mouth internal-thread cap.
Verification: Manufacturer confirmed · reviewed 2026-07-05
What it's made of
| Part | Material | Food contact |
|---|---|---|
| bottle body 18/8 (304) food-grade stainless; 90% post-consumer recycled on most Classic sizes | Stainless Steel (304 / 18-8) | Yes |
| cap (Steel Loop Cap, unibody) single piece of 18/8 stainless including the threads; no gasket, seals steel-on-steel | Stainless Steel (304 / 18-8) | Yes |
The Classic is Klean Kanteen's original narrow-mouth single-wall bottle. It ships by default with a plastic loop cap, but Klean Kanteen sells an all-steel Steel Loop Cap (for Classic narrow-mouth bottles with internal threads) that turns it into a fully plastic-free, silicone-free drink container. The same cap fits the Kid Classic narrow-mouth body, making this the plastic-free-purist option for both adults and kids who are fine with an open-mouth (no straw/spout) drinking style.
Pros
- Fully plastic-free AND silicone-free in the water path - steel-on-steel seal
- One-piece steel cap, dishwasher safe, nothing to degrade
- Same cap fits adult Classic and Kid Classic bodies
Cons
- Standard Classic ships with a plastic loop cap; the steel cap is a separate purchase
- Open-mouth drinking only - no straw or spill-proof spout, so less kid-friendly for toddlers
- Not intended for hot beverages
- Steel-on-steel seal can loosen; some users find it less leak-tight than a gasketed cap
Notes
- Steel Loop Cap fits Classic narrow-mouth bottles (internal threads) only, not wide-mouth
- Wide-mouth Classic/TKWide bodies use the Wide Loop Cap with Bale, also all-steel
- Classic bottles are single-wall (non-insulated)
Categories: Water Bottles · Kids Water Bottles
Sources
Every material claim above is backed by these. This is the scattered info we centralized.
- manufacturer https://www.kleankanteen.com/products/stainless-loop-cap Steel Loop Cap is a single piece of 18/8 stainless steel, threads included, creating a 100% stainless environment; drinks never touch plastic
- manufacturer https://www.kleankanteen.com/products/wide-loop-cap-with-bale wide-mouth equivalent (Wide Loop Cap with Bale) also 18/8 stainless, 100% stainless interior
- review https://www.bottlepro.net/hydration-blog/which-water-bottles-completely-avoid-plastic editorial roundup confirms Klean Kanteen loop caps are among the few caps with no internal plastic in the water path