Self Drilling Anchor Bolt
Self Drilling Anchor Bolt (SDA) is a new anchoring technology developed for complex geological conditions and challenging construction environments. It integrates drilling, grouting, and anchoring functions into one single process, providing high installation efficiency, reliable anchorage, and excellent adaptability to unstable ground without the risk of hole collapse. SDA bolts are widely used for slope stabilization, rockfall protection, deep foundation pits, and tunnel support.
Main Components of Self Drilling Anchor Bolt
A complete Self Drilling Anchor System consists of six major parts:
- Hollow Anchor Bar – Made from high-tensile seamless alloy steel, providing high yield and tensile strength to meet various ground conditions.
- Drill Bit – Cast from wear-resistant alloy, designed with grout outlets. Common types include cross bits, button bits, and ball bits, available as both steel and alloy types.
- Coupler – Connects anchor bars to achieve full-strength extension without grout leakage during grouting.
- Nut and Plate – The nut transfers load from the anchor bar to the plate, which distributes stress to the surrounding rock for better end bearing.
- Centralizer – Keeps the anchor centered in the borehole, ensuring even grout coverage around the bar for improved bonding and load transfer.
Self Drilling Anchor Bolt Construction Process
- Preparation: Check the drilling rig, bar, and bit for damage or blockage. Assemble the drill bit and anchor bar.
- Drilling and Grouting: Connect the bar to the grout line and drill simultaneously while injecting cement grout with a water–cement ratio of 0.4–0.5.
- Bar Extension: Use couplers to connect bars when deeper anchorage is required.
- Plate and Nut Installation: After grouting, install the plate and nut at the exposed bar end to transfer load and ensure stability.
Ensuring Quality of True SDA Bolts
A genuine Self Drilling Anchor Bolt must have equal-strength connections between the bar, coupler, and nut. Some manufacturers merely connect a hollow bar to a drill bit, which fails to meet required yield and tensile strength standards. Glory Steel Work provides certified SDA systems that meet international engineering standards for safe and reliable performance in tunneling and mining projects.
Get Your Self Drilling Anchor Bolt Quote
Contact Glory Steel Work for detailed specifications, technical support, and a competitive quotation.