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Mag Drill Capacity, Cutting Depth and RPM: Read the Limits
A mag drill's largest advertised number rarely answers the whole compatibility question. Check the machine, cutter and workpiece together. Diameter capacity, cutting depth, shank fit, mounting requirements and permitted speed describe different limits.
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Keep the capacity terms separate
A cutter's hole diameter does not describe how deep it can cut. Shank size describes its connection, not the finished hole. Available head travel also should not be substituted for a stated cutting-depth rating. Record each specification in its own field when comparing a proposed assembly.
For an actual purchase decision, write down the required hole diameter, material thickness and material grade first. Then compare those requirements with the drill manual and cutter documentation. Starting from a large cutter kit and looking for a way to fit it can obscure the original job requirements.
Use a model example without creating a universal rule
Hougen lists the HMD904 with a 7/16- to 1-1/2-inch hole range, 2-inch cutting depth and 450 RPM motor specification. These figures identify that model's published envelope; they are not a recommendation to run every cutter in every metal at 450 RPM.
Evolution's US S28MAG page lists a different maximum annular diameter, 1-1/8 inches, while also listing 2-inch depth and 450 RPM no-load speed. Matching some specifications does not make the machines' complete capacities interchangeable.
- Check annular-cutter capacity separately from twist-drill capacity.
- Match the exact cutter interface and any approved adapter.
- Confirm the material-specific cutter guidance against available machine speeds.
Inspect the exact Amazon offer
Check model, regional version, included accessories and current seller details before ordering.
Check AmazonResolve conflicts before purchasing tooling
If the cutter maker's recommended operating range does not align with the drill's available settings, ask for an approved combination rather than using an unrelated speed chart. A broad RPM range on a sales page cannot answer questions about every diameter and material.
Keep the relevant document revision and full model number with the comparison. Regional variants and kit names can complicate search results. If two official sources conflict, ask the manufacturer which applies to the unit you intend to buy. Treat unresolved compatibility as a reason to defer that purchase, not as a detail to discover during the first cut.
Questions, answered
Does a 3/4-inch shank guarantee compatibility?
No. The complete interface, machine capacity, cutter depth, pilot and application must also be appropriate.
Is no-load RPM a universal cutting recommendation?
No. It is a machine specification; select an approved machine-and-cutter combination for the actual material and diameter.
