Stainless Steel Slotted Shoulder Screws Half Threaded DIN 923 Slotted Pan Head Screws With Shoulder

説明

What Are Slotted Shoulder Screws?

Slotted shoulder screws, also known as shoulder bolts or stripper bolts, are specialized fasteners featuring a unique three-part design:

1. Threaded End – For secure fastening into tapped holes.

2. Smooth Shoulder (Unthreaded Shaft) – Provides precise alignment and acts as a pivot or bearing surface.

3. Slotted Flat Head – Allows installation with a flat-blade screwdriver, ensuring a flush finish.

These screws are engineered for applications requiring rotational movement, precise alignment, or controlled spacing, making them indispensable in machinery, automotive systems, and industrial equipment.

Materials Used in Slotted Shoulder Screws

Slotted shoulder screws are manufactured from various materials to meet different mechanical and environmental demands:

1. Carbon Steel – The most common choice, offering high strength and affordability. Often heat-treated for enhanced durability.

2. Stainless Steel (304/316) – Provides excellent corrosion resistance, ideal for food processing, marine, and medical applications.

3. Alloy Steel (A2/A4) – Used in high-stress environments where extra hardness is required.

4. Brass – Selected for electrical conductivity and corrosion resistance in low-load applications.

5. Titanium – Lightweight yet strong, used in aerospace and high-performance engineering.

Surface Finishes

To improve performance and longevity, slotted shoulder screws undergo various surface treatments:

• Zinc Plating – Basic corrosion resistance for indoor use.

• Black Oxide – Enhances wear resistance and reduces glare.

• Electroless Nickel Coating – Improves hardness and corrosion resistance.

• Passivation (for Stainless Steel) – Removes free iron particles to prevent rust.

• PTFE (Teflon) Coating – Reduces friction and provides chemical resistance.

Key Specifications

1. Dimensions

• Shoulder Diameter (D) – Typically ranges from 2mm to 20mm, with tight tolerances (e.g., g6/h7) for precision fits.

• Shoulder Length (L) – Customizable based on spacing requirements.

• Thread Size – Common metric sizes include M3 to M12, with fine or coarse thread options.

2. Head Styles

• Flat Head (Countersunk) – Sits flush with the surface.

• Pan Head – Slightly rounded for better torque distribution.

• Low-Profile Head – Minimizes protrusion in tight spaces.

3. Drive Types

• Standard Slotted – Simple and widely compatible.

• Combination Slotted/Hex – Allows both screwdriver and wrench use for higher torque.

Applications of Slotted Shoulder Screws

✅ Precision Machinery – Used in gears, linkages, and rotating assemblies where smooth shoulder movement is critical.
✅ Automotive Systems – Found in throttle linkages, brake mechanisms, and transmission components.
✅ Mold & Die Making – Essential for guiding ejector pins in injection molds.
✅ Electronics & Robotics – Provides low-friction pivots in robotic arms and PCB fixtures.
✅ Medical Devices – Used in surgical instruments and imaging equipment due to biocompatibility (when made from stainless steel or titanium).

Excellent Case: High-Speed Packaging Machine Alignment System

Project Overview

A food packaging manufacturer needed a high-speed conveyor system that could handle 300+ packages per minute without misalignment. The challenge was ensuring that the guide rails remained perfectly parallel while allowing slight adjustments for different package sizes.

Solution: Slotted Shoulder Screws in Action

1. Precision Alignment

   • M8 × 40mm stainless steel shoulder screws were installed at pivot points.

   • The smooth shoulder allowed the guide rails to rotate smoothly, while the threaded end secured them to the frame.

2. Easy Adjustability

   • The slotted heads enabled quick adjustments with a flat-blade screwdriver.

   • The unthreaded shaft prevented binding, ensuring smooth movement.

3. Corrosion Resistance

   • 316 stainless steel with passivation was chosen to withstand frequent washdowns in the food processing environment.

Results

• Zero misalignments even after 6 months of continuous operation.

• Reduced maintenance due to the screws’ wear-resistant design.

• Easy reconfiguration for different package sizes, improving production flexibility.

Why Slotted Shoulder Screws Are Essential

Slotted shoulder screws bridge the gap between fastening and motion control, offering:
✔ Precise alignment for mechanical linkages.
✔ Reduced friction due to the smooth bearing surface.
✔ Easy installation & adjustment with slotted drive.
✔ Longevity with corrosion-resistant coatings.

For optimal performance:

• Match shoulder diameter to bushing/bearing requirements.

• Select the right material for environmental conditions.

• Use thread-locking compounds if vibration is a concern.

Whether in industrial automation, automotive systems, or medical devices, slotted shoulder screws provide reliable, adjustable, and long-lasting performance in critical applications.