Application guide for Slotted Oval Head Machine Screws, UNC to ASME B18.6.3. The core duty of the type is inch slotted oval countersunk head machine screws with UNC thread. The typical industries, the how-to-specify checklist, assembly practice and the exclusion cases are set out below. Stocked across roughly 1 to 12, they cover general to heavy-duty work.
Typical Applications for Slotted Oval Head Machine Screws, UNC
The most common settings where these are specified:
- Electrical: switch plates.
- Furniture: decorative.
- Restoration: period hardware.
- Marine: trim.
How to Specify Slotted Oval Head Machine Screws, UNC for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans 1–12; check the full table below for the exact dimensions of each size.
- Drive & head: Pick the drive (socket, cross, slot) and head style for the tool access and seating surface; a recessed drive resists cam-out under power tools.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to ASME B18.6.3. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Installation & Assembly Practice
- Match the driver exactly to the recess (PH ≠ PZ; hex key sizes per ISO 2936) and keep the tool axial — side load is the main cause of stripped drives.
- In tapped holes, engage a thread length of at least 1× the nominal diameter in steel, 2× in aluminum.
- Set power tools to a torque that seats the head without embedding it into the mating surface.
Common Selection Mistakes with Slotted Oval Head Machine Screws, UNC
- Under-sizing the drive for the installation torque — a small recess at high torque strips before the screw is seated.
- Using a countersunk head in thin sheet where the countersink removes most of the load-bearing material.
- Specifying stainless in high-strength duty: A2-70 is roughly class 7 steel, not a 10.9 substitute.
Where Slotted Oval Head Machine Screws, UNC Are Not the Right Choice
Not for high-preload structural joints (use a property-class bolt and nut), and not in thin sheet where a self-drilling or self-tapping type suits better.
Custom manufacturing · Made to drawing
Need a slotted oval head machine screws, UNC outside the standard range?
Thread size and pitch, length, property class, drive form, head geometry and head marking are all specifiable — the standard part is where it starts, not where it stops. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

