Definition
Tool accessibility is the specific question of whether a given tool and holder combination can physically reach a feature to cut it, considering not just the cutting edge but the tool's full length, diameter and the holder behind it, against the surrounding geometry of the part and fixture.
Why tool accessibility is more than a cutting-edge question
A feature can fail on tool accessibility even when a tool exists that could theoretically cut it, if the holder collides with a nearby wall before the cutting edge reaches the feature, which is a common and easy to overlook manufacturability issue.
How tool accessibility is checked
Not shown directly; assessed by checking feature depth and surrounding geometry against the reach and diameter of available tools and holders for a given setup.
Common mistakes
Checking whether the cutting edge can reach a feature but forgetting the holder behind it, which is often the actual limiting factor in a deep or tightly surrounded feature.
A feature can fail on tool accessibility even when a tool exists that could theoretically cut it, if the holder collides with a nearby wall before the cutting edge reaches the feature, which is a common and easy to overlook manufacturability issue.
See how Blake reviews a partFrequently asked questions
Is tool accessibility the same as accessibility in general?
Tool accessibility is the specific, tool-and-holder version of the broader accessibility question for a feature.
Why does the tool holder matter, not just the cutting edge?
Because the holder is usually wider than the cutting tool and can collide with surrounding geometry before the tip reaches the feature.
Can a tool accessibility problem be solved without redesigning the part?
Sometimes, with a longer or thinner tool, a different holder, or a different setup orientation; otherwise the feature itself may need to change.