Square Hole Drill Bit Adapter Fixing Bracket Clamp Diameter between 38mm to 55mm Bench Drill Press Converter for Drill Machine Attachment With 4 Screws.The square hole drill fixed bracket is made of high quality stainless steel material, wear resistant, high hardness, sturdy and durable.The square hole drill bit adapter is fit for table drill and hand drill clamp with a diameter between 38mm to 55mm/1.5 to 2.2inch.The square hole drill bit adapter converter is easy to install and remove, you can quickly install or remove it yourself, fast and convenient.Square hole drill bit adapter, products do not include square hole drill and electric drill, dual use support bracket for table drill and hand drill.The square hole drill bit adapter bracket is perfect for woodworking and furniture making, ensuring accurate and drill.Square Tenon Machine Accessories for Bench Drill. Square Tenon Machine Converter Location Tool. Clamp Diameter 38~55mm Guide Handheld Press Vice. Location Tool Portable Drill Press Stand. Log Furniture Bench Drill Square Hole Accessories.