M6x6 Socket Flat Point Set Screws: Fit and When to Use Them
By Products for bench top machinists | LittleMachineShop.com | Published: 2026-11-04
Category: ヒントとお手入れ
Learn where an M6x6 socket flat point set screw fits on the SC4 bench lathe, how flat points differ from cup points, and practical installation and loosening fixes.
Quick answer
Use an M6x6 socket flat point set screw when you need a secure, non-marring clamp on a flat surface and have a shallow 6 mm engagement depth. On the SC4 bench lathe, it is the replacement for the half nut lever handle set, part #308.
Why the SC4 half nut lever uses a flat point
The half nut lever handle set on the SC4 relies on a flat point to press against a flat mating surface without digging in. That makes removal and readjustment easier than a cup point, which bites into the shaft and can raise a burr over time.
When a cup point is the better choice
Cup points excel where vibration is high and the screw must not back out, such as on a pulley or collar that sees constant rotation. The trade-off is that the cup point permanently marks the shaft, so reserve it for components you do not plan to reposition often.
Set screw questions answered
- What does an M6x6 set screw fit?
- The M6x6 size means a 6 mm metric thread and 6 mm overall length. On the SC4 bench lathe it is the specified replacement for the half nut lever handle set (part #308). For other assemblies, check the parts diagram for the required length before ordering.
- Flat point vs cup point: which should I use?
- Choose flat point for flat surfaces or when you need to adjust or remove the joint without damaging the shaft. Choose cup point when maximum holding power on a round shaft matters more than surface finish.
- How do I install a set screw without stripping the socket?
- Seat the screw by hand first, then tighten with a properly sized hex key. Apply moderate torque—enough to hold the component without crushing the threads. For flat points, snug is usually sufficient; over-tightening adds little holding force and risks socket damage.
- What should I do if the set screw keeps loosening?
- First check that the screw length matches the application and that the point contacts the flat properly. If it still backs out, clean the threads and apply a removable threadlocker such as blue Loctite. Avoid permanent threadlocker on parts you may need to adjust.
Product facts
- Set Screw, M6x6, Socket Flat Point: M6 x 6 mm socket flat point set screw, listed as part #308 for the SC4 half nut lever handle set. Ordering this exact size restores the lever action without modifying the handle or shaft.
Set Screw, M6x6, Socket Flat Point
