A4-70 Stainless Steel Pan Head Screws with Lock Washers 316

A4-70 SS Pan Head Screws with Lock Washers 316 Stainless Spring + Flat Washer Salt Water Resistant Custom

Premium A4 stainless Phillips pan head screws with pre-assembled spring & flat washers. Passivated finish for marine, chemical & food processing. Vibration proof & corrosion resistant. M4-M12 sizes. Custom options.

Secure critical assemblies in corrosive environments with our **A4 Stainless Steel Phillips Pan Head Machine Screws with Pre-Assembled Spring and Flat Washers**. Crafted entirely from A4-70 (316) stainless steel, this complete set offers **superior resistance** to salt water, chemicals, acids, and humidity, combined with **vibration-resistant locking**. The pre-assembled flat washer distributes load, while the spring washer prevents loosening. Ideal for **marine hardware, chemical processing equipment, food machinery, coastal infrastructure, and outdoor applications** demanding maximum durability and reliability. Passivated finish standard.

Primary Uses & Applications:

* Marine deck hardware, hatches, and fittings.
* Offshore platforms & equipment.
* Chemical plant piping, valves, and instrumentation.
* Food & beverage processing machinery.
* Pharmaceutical equipment.
* Coastal structures (railings, signs, enclosures).
* Outdoor power generation equipment.
* High-humidity HVAC & ventilation.
* Any application requiring corrosion resistance *and* vibration proofing.

Surface Treatment/Finishes:
* **Passivation (Standard):** Mandatory chemical process removing free iron and enhancing the chromium oxide layer for maximum corrosion resistance. Applied to entire assembly.
* **Electropolishing (Optional):** Provides a smoother, brighter, more hygienic surface, further boosting corrosion resistance and cleanability. Ideal for food, pharma, and high-purity applications.

How to Use:

1. **Prevent Galling:** **Crucial!** Apply **stainless steel anti-seize compound** to the screw threads before installation, especially for stainless-on-stainless contact.
2. **Prepare:** Ensure female threads (nut/tapped hole) are clean, compatible (preferably A2/A4 SS), and deburred.
3. **Insert Assembly:** Place through clearance hole. Flat washer contacts bearing surface; spring washer between flat washer and head.
4. **Drive:** Use the **correct Phillips driver**. Apply **steady, moderate pressure and speed** (no high RPMs) to minimize heat/galling risk.
5. **Tighten:** Tighten until the spring washer is **slightly compressed** (provides locking force). **Avoid over-tightening.** Refer to A4 stainless torque specs.
6. **Function:** **Flat Washer** protects surfaces & distributes load. **Spring Washer** maintains tension against vibration/thermal cycling. **A4 Material** resists corrosion.
7. **Removal:** Anti-seize should aid removal. If galling occurs, do not force.

Dongguan Guanbiao Hardware Products Co., Ltd., established in 2013, is a screw hardware processing factory integrating R & D, production and sales, focusing on electronic and electrical appliances, computer radiator, communication equipment, lighting, motor, motor, medical equipment, sports equipment, auto parts, baby stroller accessories and other industries. Its main products include all kinds of iron, stainless steel, copper, aluminum and alloy Precision small screws, spring screws, loose screws, stainless steel screws, step screws, plum blossom screws, slender screws, anti-theft screws, non-standard customized screws, stainless steel rivets, shafts, pins, CNC parts and stamping parts. The first mock exam the second mock exam is two punch, two die four punch, three die six punch, four die four punch, six die six punch, die closing machine, part forming machine, automatic lathe, CNC lathe and so on, and the diameter is 1mm-20mm, the length is 1mm-300mm.

The company introduced imported automation equipment, combined with mature technology and precision equipment, to ensure product quality, control quality from the source, and adhere to technological innovation.

Our business philosophy is "integrity, innovation, efficiency, win-win", your satisfaction is our eternal pursuit, looking forward to become your sincere partner!    wechat:+8613423026460