Material:carbon steel&stainless steel Not require precise hole depth or hole cleaning out. Anchor can be hammered below the surface of the concrete when no longer needed. The one piece clip is formed around Anchor.assuring full expansion for dependable, superior holding prower.Expanding clip will not fall off or twist in the hole. The test values listed beneath were obtained using 200-250kgs/cm concrete (no aggregate). A safe working load should not exceed 25%of stated value.