File contents Fastener Hole Patterns
Create standard fastener holes: clearance, counterbore, or countersink.
Hole types
Clearance holes (through-hole for bolt to pass through)
Size
Close fit
Normal fit
M2
2.2mm
2.4mm
M2.5
2.7mm
2.9mm
M3
3.2mm
3.4mm
M4
4.3mm
4.5mm
M5
5.3mm
5.5mm
M6
6.4mm
6.6mm
M8
8.4mm
9.0mm
Counterbore (socket head cap screw)
Size
CB diameter
CB depth
M3
6.5mm
3.0mm
M4
8.0mm
4.0mm
M5
10.0mm
5.0mm
M6
11.5mm
6.0mm
M8
15.0mm
8.0mm
Countersink (flat head screw, 90 degree)
Size
CS diameter
M3
6.3mm
M4
8.4mm
M5
10.4mm
M6
12.6mm
Parameters to ask (if not provided)
Screw size : M2 through M8Hole type : clearance / counterbore / countersinkFit : close / normal (for clearance holes)Target object : body or feature to cut intoPositions : list of XY coordinates, or pattern (linear/circular)Pattern : if applicable — count, spacing, or bolt circle diameter + count
Construction
Create a sketch on the specified face
For each hole position, add a circle (clearance diameter)
Pocket through-all for the clearance hole
For counterbore: add a second larger circle, pocket to CB depth
For countersink: use a cone (Part.makeCone) to create the 90-degree chamfer
Cleanup
After construction, hide all sketches for a clean viewport:
for obj in App.ActiveDocument.Objects:
if obj.TypeId == "Sketcher::SketchObject":
obj.Visibility = False
1 --- 2 name: fastener-hole 3 description: Fastener Hole Patterns 4 --- 5 # Fastener Hole Patterns 6 7 Create standard fastener holes: clearance, counterbore, or countersink. 8 9 ## Hole types 10 11 ### Clearance holes (through-hole for bolt to pass through) 12 | Size | Close fit | Normal fit | 13 |------|-----------|------------| 14 | M2 | 2.2mm | 2.4mm | 15 | M2.5 | 2.7mm | 2.9mm | 16 | M3 | 3.2mm | 3.4mm | 17 | M4 | 4.3mm | 4.5mm | 18 | M5 | 5.3mm | 5.5mm | 19 | M6 | 6.4mm | 6.6mm | 20 | M8 | 8.4mm | 9.0mm | 21 22 ### Counterbore (socket head cap screw) 23 | Size | CB diameter | CB depth | 24 |------|-------------|----------| 25 | M3 | 6.5mm | 3.0mm | 26 | M4 | 8.0mm | 4.0mm | 27 | M5 | 10.0mm | 5.0mm | 28 | M6 | 11.5mm | 6.0mm | 29 | M8 | 15.0mm | 8.0mm | 30 31 ### Countersink (flat head screw, 90 degree) 32 | Size | CS diameter | 33 |------|-------------| 34 | M3 | 6.3mm | 35 | M4 | 8.4mm | 36 | M5 | 10.4mm | 37 | M6 | 12.6mm | 38 39 ## Parameters to ask (if not provided) 40 - **Screw size**: M2 through M8 41 - **Hole type**: clearance / counterbore / countersink 42 - **Fit**: close / normal (for clearance holes) 43 - **Target object**: body or feature to cut into 44 - **Positions**: list of XY coordinates, or pattern (linear/circular) 45 - **Pattern**: if applicable — count, spacing, or bolt circle diameter + count 46 47 ## Construction 48 1. Create a sketch on the specified face 49 2. For each hole position, add a circle (clearance diameter) 50 3. Pocket through-all for the clearance hole 51 4. For counterbore: add a second larger circle, pocket to CB depth 52 5. For countersink: use a cone (Part.makeCone) to create the 90-degree chamfer 53 54 ## Cleanup 55 After construction, hide all sketches for a clean viewport: 56 ```python 57 for obj in App.ActiveDocument.Objects: 58 if obj.TypeId == "Sketcher::SketchObject": 59 obj.Visibility = False 60 ```
commit 2a6fc4cfaf
Frequently asked questions How do I install the Fastener Hole skill? Run npx skillmds@latest add ghbalf/fastener-hole in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.
What does the Fastener Hole skill do? Fastener Hole Patterns It is listed under Coding & Dev Tools on SkillMD.
Is Fastener Hole safe to use? This skill has not completed SkillMD's automated safety review yet. Capability flags: docs only. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.
Which AI agents work with Fastener Hole? This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.
Is Fastener Hole free to use? Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.
Who published Fastener Hole? ghbalf (@ghbalf) published this skill. Their other Agent Skills are listed on their SkillMD profile.
ghbalf