What Type Of Din571 Wood Lag Screws Are

Posted by Head WoodScrews on June 30th, 2017

A wood lag screws is a screw that taps its own threads when screwed into a hole. When tapping threads into masonry, the lead thread does all of the cutting of the masonry material and is designed to cut threads up to 1-3/4” in depth. The abrasiveness of the masonry will determine the exact depth that any specific screw can tap. The lead thread will dull and hit a point where it will no longer be able to cut threads and will stop screw penetration.

However, as the threads are cutting into the masonry, dust is created. The threads are designed to allow the dust to be removed and to prevent interference with the screw installation. Therefore, the hole drilled in the masonry must be slightly deeper than the screw will penetrate to allow space for the dust that is created during the taping process to fall into and out of the way.

The hole diameter is critical and must be drilled in accordance with the manufacturer’s instructions. The guidelines for masonry screw anchors are as follows: the 3/16” diameter requires the hole diameter to be equal to 5/32” and the 1/4” diameter requires a 3/16” hole. The hole must be drilled using a carbide drill bit that meets ANSI standards. ANSI standards ensure proper hole dimension tolerance requirements. Any variance in hole size will affect the holding values and may make the holding values not existent.

Once the hole is drilled, it must be cleaned of all dust and debris, otherwise, holding values may be affected. Using a wire brush, compressed air or vacuum in combination is usually sufficient to clean out the hole before inserting the screw.

Masonry screw anchors are available in two different head styles designed for different types of applications. If the application calls for the head to be countersunk in the material being fastened, then the flat countersunk phillips screw should be used. If the head of the screw will be on top of the surface of the material being fastened, then the hex washer head should be used.

Masonry self tapping screws are manufactured from carbon steel that has a blue coating or from a 410 stainless steel which also has a protective coating. The standard blue coated self tapping screw is for use in indoor applications where moisture is not present. While for outdoor use or in moist atmospheres, the 410 stainless steel should be used. wood lag screws - http://www.din571.com/