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Finish Line Factory technical library
AN dash size describes tube outside diameter in sixteenths of an inch. A -8 AN connection corresponds to 1/2-inch tube OD; it does not guarantee a 1/2-inch hose bore. AN fittings seal at a 37° flare.
On small screens, scroll the table sideways to see all columns.
| AN size | Tube OD (in) | Nominal hose ID (in) | Approximate hose ID (in)* | Fitting thread |
|---|---|---|---|---|
| -3 | 3/16 | 3/16 | 1/8 | 3/8-24 |
| -4 | 1/4 | 1/4 | 3/16 | 7/16-20 |
| -5 | 5/16 | 5/16 | 1/4 | 1/2-20 |
| -6 | 3/8 | 3/8 | 5/16 | 9/16-18 |
| -8 | 1/2 | 1/2 | 7/16 | 3/4-16 |
| -10 | 5/8 | 5/8 | 1/2 | 7/8-14 |
| -12 | 3/4 | 3/4 | 5/8 | 1-1/16-12 |
| -16 | 1 | 1 | 7/8 | 1-5/16-12 |
| -20 | 1-1/4 | 1-1/4 | 1-1/8 | 1-5/8-12 |
*Supplier approximate bore values are a reference only. Use hose-family specifications for actual dimensions.
Maximum torque
| AN size | Maximum ft-lb |
|---|---|
| -3 | 9 |
| -4 | 12 |
| -6 | 16 |
| -8 | 29 |
| -10 | 35 |
| -12 | 45 |
| -16 | 70 |
| -20 | 85 |
These are maximum limits, not universal tightening targets. Over-tightening can damage the flare. Match the component instructions, material and lubrication requirements.
Identify the seal
AN flare, ORB and NPT use different sealing methods. A matching thread alone is insufficient. Do not combine 37° AN and 45° SAE seats. AN bolt numbering also differs from fitting numbering. Shop AN fittings and adapters.
Shop & get help
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Technical reference: FLF Racing Supply / Finish Line Factory. Checked October 6, 2026. Use the instructions for your exact components.