1.When Two Workpieces Are Processed into a 45 Edge Bevel, Then Clean the 45 Face of Workpiece, Evenly Coated with Adhesive, Then Put Two Workpiece of 45 Bevel Face Assembling Together, and the Two 45°Workpiece Fit into a 90 with Each Other, Use the Fixture in Plastic Extrusion Seam Stitching. 2.First, Put the Bottom of Width Stone on the Fixture Work Surface Which with White Rubber, the Side of the Narrow Stone Close to the 90 Inside of the Fixture. 3.Then Two Binder Lever Can Be Adjusted by Adjusting Spring Device Access to the Top Position of the Workpiece,Then Rotating the Screw at the Top of the Binder Lever to Put Pressure in Place to Maintain the Fixture Locked Position for a Certain Time, Until the Workpiece Fully Bonded Joints, Solid, and Then Release the Fixture.