1-1/4 in.
This size is light and maneuverable for smaller tools, sanders and accessories. Bosch, for example, provides adapters for connecting 1-1/4 in. hoses to its router dust hoods.
1-7/8 in.
1-7/8 in. is a common compromise on portable vacuums: more area than a small hose while remaining easier to handle than 2-1/2 in. RIDGID sells a professional 1-7/8 in. hose with adapters for its 2-1/2 in. inlets and accessories.
2-1/2 in.
2-1/2 in. is suitable for larger debris and benchtop tools when the vacuum supports it. RIDGID describes this opening as appropriate for large-debris cleanup and uses it across multiple vacuum systems.
Frequently Asked Questions
Which hose size is best for a sander?
A smaller flexible hose is often easier to handle, but start with the size specified by the sander and extractor manufacturer.
Which hose size is best for a table saw or miter saw?
When the machine provides a 2-1/2 in. port and the vacuum supports it, keeping that size avoids an unnecessary reduction.
Can I reduce 2-1/2 in. to 1-1/4 in.?
Yes mechanically with the right adapter, but the reduction limits flow area and can affect collection performance.
Technical Sources
The sizes and part references in this guide are based on the following official pages: RIDGID 1-7/8 in. hose RIDGID 2-1/2 in. hose Bosch RA1173AT.
Disconnect the machine before measuring or installing a fitting. Check the manufacturer manual, keep guards in place and never force a connector whose geometry does not match.