Module 3 sur 10 200m 200 min 6 exam Qs 6 exam questions covered
Benchwork, Layout & Hand Tools
Layout dye application, filing techniques, hand reaming, tapping procedures, and thread sizing for benchwork operations.
- Explain layout dye application and marking techniques
- Describe filing, reaming, and hand tool operations
- Calculate tap drill sizes and demonstrate proper tapping technique
Leçon 1
Layout Dye & Marking Techniques
Purpose of Layout Dye
Layout dye (Dykem) is applied to a workpiece surface to make scribed lines more visible. The thin blue or red coating creates a high-contrast background against which scribed layout lines show as bright, clear marks. Without layout dye, scribed lines on bare metal surfaces are difficult to see.
Application steps:
- Clean the workpiece surface to remove oil, chips, and debris
- Apply a thin, even coat of layout dye (brush or spray)
- Allow to dry completely (1-2 minutes)
- Scribe layout lines using a scriber, height gauge, or dividers
Exam Tip
Layout dye does NOT prevent rust, lubricate surfaces, or harden the workpiece. Its sole purpose is to make scribed lines more visible.
Layout Tools
- Scribers - hardened steel or carbide points for marking lines
- Dividers - for scribing arcs and transferring measurements
- Hermaphrodite calipers - one leg has a point, one has a curved end for scribing lines parallel to an edge
- Combination square - for 90-degree and 45-degree layout lines
- Center punch - marks drill locations and prevents drill walking
Key Takeaway
Layout dye (Dykem) makes scribed lines more visible on metal surfaces. It does not protect, lubricate, or harden the surface. Always apply dye to a clean, dry surface.