M16 is one of the standard coarse-thread sizes for flat plain washer under GB/T 95 / ISO 7091. The sections below reproduce the dimensional row, list the matching tools and hole sizes, and summarize where this size is normally specified.
M16 Dimensional Row (GB/T 95 / ISO 7091)
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|
| M16 | 17.0 | 30.0 | 3.0 | ISO 7089 / GB/T 97.1 |
Spanner & Drive for M16 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079)
Drive geometry for M16 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079) is given by the row above; match the tool to the listed values.
Common Applications for M16 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079)
M16 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079) are commonly specified for medium-duty structural joints.
Mating Parts for M16
A M16 flat washer pairs with a M16 bolt/screw and matching M16 nut.
When to Step Up or Down from M16
When the joint preload approaches the proof load of M16 class 8.8, step up to M20 class 8.8 (or move to M16 class 10.9). When the joint is over-specified, M12 often saves weight and cost without losing the safety margin.