Drop-in Anchors

Technical Information

There is some technical information that must be considered when installing and using concrete drop-in anchors. These concrete anchors are available in Richmond Threads for rebar reinforcement. These drop-in anchors come in different types of steel including zinc plated carbon steel and stainless steel. Some other important things to consider when using this type of concrete anchor is size of anchor, anchor length, drill bit size, thread length as well as bolt diameter. A drop-in anchor can handle Pull Outs up to 13,600 lbs.

Anchor Spacing: The forces on a Drop-In Anchor are transferred to the material that it is installed in. If the anchors are installed too close together, it can cause an interaction of the forces, thus reducing the holding power of the anchor. As a rule of thumb, the expansion industry has established a minimum standard of ten (10) anchor diameters for spacing between anchors and five (5) anchor diameters from an unsupported edge. When vibration or sudden impact is part of the load condition, spacing between anchors should be increased.

Bolt Length: Bolt length equals thread length of anchor plus thickness of material to be fastened.

Size	Length	Drill Bit	Thrd. Length	Bolt Dia.	Pull Out
1/4”	1”	3/8”	7/16”	1/4”	2300 lb
3/8”	1-9/16”	1/2”	5/8”	3/8”	4100 lb
1/2”	2”	5/8”	1-3/16”	1/2”	6000 lb
5/8”	2-1/2”	7/8”	1-3/16”	5/8”	8300 lb
3/4”	3-3/16”	1”	1-3/16”	3/4”	13600 lb
Values shown are average ultimate values and are offered only as a guide and are not guaranteed . A safety factor of 4:1 or 25% is generally accepted as a safe working load. Reference should be made to applicable codes for the specific working ratio. Minimum embedment is equal to anchor length.