Elco EAF900 DrilFlex 1/4-20 x 3-3/8" HWH #4 Point - 500 Screws

DrilFlex® fasteners are specially designed and processed to help prevent hydrogen-induced brittle failures. Each fastener undergoes a unique dual-hardening process to ensure the optimal combination of ductility and hardness required for maximum performance in the field.

Testing of this product, in accordance with ASTM standards, has proven that DrilFlex fasteners provide the same resistance to hydrogen-assisted cracking (HAC) as a Grade 5 fastener.

Hydrogen-Assisted Cracking (HAC) refers to any time-delayed failure mechanism that is aggravated or accelerated because of the presence of hydrogen. Most self-drilling fasteners are case-hardened, which provides the necessary hardness for drilling and tapping, but leaves the screws vulnerable to HAC due to their high surface hardness.

DrilFlex fasteners offer a unique dual-hardening process. The self-drilling point and lead tapping threads are selectively hardened to a minimum of HRC 52. The load-bearing portion of the screw is held at or below the critical HRC 34 level. This reduced hardness level also meets SAE J429 Grade 5 and ASTM A449 strength and ductility standards.

DrilFlex fasteners are then coated with Stalgard® finish to provide superior corrosion resistance. Fasteners coated with Stalgard finish typically show no red rust or other base metal corrosion on significant surfaces even after 800 hours of 5% neutral salt spray exposure (ASTM B117).

Specifications:

• Size: 1/4-20
• Length: 3-3/8"
• Head Style: HWH #4 Point
• Load Bearing Area: 2.70"
• Drilling Capacity: .210" to .312"
• Application Use: Steel and Aluminum

Features:

• Self-drilling point
• Higher hardness (HRC 52 min.)point and lead threads
• Lower-hardness (HRC 28 – 34)load-bearing threads
• Silver Stalgard® multi-layered corrosion resistant finish