Wescon 690 Microstop, 3/8-24, 7/8" Cap, Straight, Tri-Flat - WES690-875-TF

The Wescon Model 690 Microstop – Wescon 690 Microstop - 3/8-24 - 7/8" Cutter Capacity - Straight Skirt (WES690-875-TF) is a precision countersink cage engineered for consistent, repeatable depth control in demanding drilling operations. Optimized for aircraft manufacturing, airframe overhaul, and MRO environments, this microstop helps aviation maintenance teams achieve clean, uniform countersinks with minimal setup time.

Key Features:

• Designed to support common aerospace rivet and fastener countersink diameters
• Straight Skirt provides stable guidance and positive depth control on curved and flat airframe surfaces
• Contact surface is engineered to balance control with minimal marking on finished materials
• Fine depth adjustment mechanism allows incremental changes for accurate countersink depth matching fastener head height
• Designed for use with high-speed hand drills and production drill motors commonly used in aircraft assembly
• Compatible with standard threaded countersink cutters for flexible shop integration
• Robust internal bearing and thrust arrangement supports smooth rotation under axial load
• Compact body profile improves access to tight structural recesses and overlapping skin joints
• Built to withstand daily use in aviation manufacturing, modification, and maintenance hangars

Specifications:

• Model: 690
• Thread: 3/8-24 Thread
• Cutter Capacity: 7/8" Capacity
• Skirt Style: Straight Skirt
• Shaft Style: Tri-Flat Shaft

Whether you are countersinking skins on a production line, repairing a pressure bulkhead, or performing structural modifications during an inspection, this Wescon microstop delivers the control and reliability aviation technicians expect. Pair it with the appropriate Wescon or equivalent countersink cutter, set your depth, and achieve clean, repeatable results across aluminum alloys, composites, and typical aircraft structures.