SealSpec / O-rings / Size chart / AS568-390

AS568-390 O-ring · 21 ID × 3/16 cross-section

Standard AS568 size -390: 20.955 in inside diameter × 0.210 in cross-section (532.26 × 5.33 mm). Dimensions, tolerances, groove check and material options for specifying this size in a production design.

AS568-390 O-ring dimensioned drawing, 20.955 inch ID by 0.210 inch cross-section, outside diameter 21.375 inch — Dimensioned drawing, proportional to ID/CSDownload SVG

Dimensions (inch)

Dash number	AS568-390
Inside diameter	20.955 ± 0.095
Cross-section	0.210 ± 0.005
Outside diameter (calculated)	21.375
Nominal	21 × 21 3/8 × 3/16

Dimensions (mm)

Inside diameter	532.26 ± 2.41
Cross-section	5.33 ± 0.13
Outside diameter (calc.)	542.92

Material options for -390

Viton / FKM Nitrile / Buna-N EPDM Silicone Fluorosilicone Neoprene

Check your groove for -390

Enter your gland dimensions. Results are nominal geometry.

Groove depth (in)Groove width (in)Installed ID / rod (in)

Open the full groove calculator →

Same cross-section (0.210 in)

-386 16.955 -387 17.955 -388 18.955 -389 19.955 -390 20.955 -391 21.955 -392 22.940 -393 23.940 -394 24.940

← AS568-389 · AS568-391 → · Full size chart