DRAWING DETAILS / CNC MACHINING INSIGHTS
Bosses and standoffs often support a cover, PCB, bracket or another mounted component. Their height, hole type and location only make sense when the drawing shows the mounting relationship. Clear notes turn a simple raised feature into a reviewable requirement.
Start with the mounted component
Identify what the boss supports or locates. Does it set a spacing height, receive a fastener, clear a component, or establish a mounting face? The mating part or hardware may be the quickest way to explain the feature’s purpose in an RFQ.
Our assembly-fit guide outlines the useful context to include when a feature cannot be understood from the individual part alone.
Define the complete feature
| Feature detail | Useful drawing information |
|---|---|
| Height | Dimension from the functional base face or mounting reference. |
| Outside profile | Show the shape that provides clearance or supports the mating part. |
| Hole type | State clearance, through, blind or thread requirement independently. |
| Mounting relationship | Show the supported surface, mating feature or required spacing. |
A section view is especially useful where a boss contains a hole or thread and the required height is not obvious in a plan view.
Keep the height tied to a functional reference
A standoff height matters because it relates one assembly surface to another. Show the face from which it is controlled, and identify the mating surface if that relationship affects fit. Our CNC drawing datums guide provides a practical framework for selecting drawing references that reflect assembly function.
Specify threads and hole details separately
A boss with a threaded feature needs a complete thread callout; a boss with a clearance hole needs its own hole definition. Do not assume the feature name communicates thread size, depth or entry side. See our thread specification guide for the related drawing details.
Focus inspection on the interface
If boss height, location or contact surface affects assembly, identify it in the inspection expectations before release. A useful requirement points to the functional relationship rather than treating every external feature as equally critical.
Make the mounting feature clear
ExactMach coordinates drawing-defined CNC milling, CNC turning, prototypes and custom parts around Shenzhen and Dongguan for international orders. Clear boss and standoff notes help establish the released mounting requirement before production begins.