Question 1

What is the ACI 318-19 anchor load calculator?

Accepted Answer

The BuildToolHQ Anchor Load Calculator computes tensile and shear capacity for concrete anchors per ACI 318-19 Chapter 17. Enter your anchor diameter, embedment depth, concrete strength, and edge distance to get instant phi-reduced capacity values for steel failure, concrete breakout, and governing capacity.

Question 2

How do I calculate concrete anchor load capacity?

Accepted Answer

Anchor load capacity depends on anchor diameter, embedment depth, concrete compressive strength (f'c), edge distance, and whether concrete is cracked or uncracked. The ACI 318-19 Chapter 17 method calculates steel tensile strength (phiN_sa), concrete breakout strength (phiN_cb), and governing capacity (phiN_n = minimum of the two). Our calculator performs all these calculations instantly.

Question 3

What is embedment depth for concrete anchors?

Accepted Answer

Embedment depth (h_ef) is the length of the anchor embedded in the concrete, measured from the concrete surface to the anchor tip. Deeper embedment increases load capacity. Minimum embedment is typically 3x the anchor diameter. Our calculator checks this minimum automatically and flags violations.

Question 4

What is the difference between cracked and uncracked concrete for anchor design?

Accepted Answer

Cracked concrete has lower anchor capacity than uncracked. ACI 318-19 requires cracked concrete values unless the concrete can be confirmed uncracked. The cracked/uncracked condition affects the psi_c modification factor - 1.0 for cracked, 1.25 for uncracked concrete in tension calculations.

Question 5

How much does a 1/2 inch wedge anchor hold?

Accepted Answer

A 1/2 inch wedge anchor in 3,000 psi concrete with 3.5 inch embedment typically provides 7,000-9,000 lbs tensile capacity and 4,000-5,000 lbs shear capacity (phi-reduced per ACI 318-19). Actual values depend on edge distance, anchor spacing, concrete condition, and phi factor. Use our Anchor Load Calculator for your specific conditions.