Trimco 3910 Dust Proof Strike

About this item

The Trimco 3910 is a dust proof strike from Trimco's flush bolt accessory line, designed specifically for use with Trimco 3800 Series automatic and semi-automatic flush bolts. It is also compatible with Trimco manual flush bolt assemblies. BHMA standard L04021. American Locksets is an authorized Trimco dealer stocking the 3910 in 630 Satin Stainless Steel and additional finishes with same-day shipping and free shipping on orders over $300.

What a Dust Proof Strike Does and Why It Gets Specified

A dust proof strike is the floor-mounted receiver for the bolt on an inactive door leaf in a pair of doors. When the inactive leaf is closed, the flush bolt drops into the dust proof strike and holds the door in position. Without a dust proof strike, the floor bolt lands directly in a drilled hole in the floor, which collects dust, debris, and moisture over time. A clogged floor hole causes the bolt to stick, bind, or fail to engage fully, creating both a security failure and an egress compliance issue.

The dust proof strike solves this by providing a spring-loaded cover plate over the floor recess. The cover holds closed when the bolt is retracted, keeping the receiver hole clean. When the bolt drops into the strike, it depresses the spring-loaded cover, seats fully, and holds the door securely. This keeps the mechanism clean across years of use in high-traffic commercial, institutional, and government buildings where a raw drilled floor hole would foul within weeks.

Trimco 3910 Specifications

• SKU: 3910 630

• BHMA Standard: L04021

• Overall Dimensions (with faceplate): 3/32 inch x 1-5/16 inch x 2-1/2 inch

• Depth: 1-1/2 inch

• Target Area: 3/4 inch diameter, allowing the flush bolt to engage reliably even with minor bolt misalignment

• Spring: Soft spring mechanism aids ADA compliance by reducing the force required for the bolt to seat

• Compatible Flush Bolts: Trimco 3800 Series Automatic Flush Bolts, 3800 Series Semi-Automatic Flush Bolts, and Trimco Manual Flush Bolt assemblies

• Available Finishes: Brass, Bronze, Plated, Stainless Steel. 630 Satin Stainless Steel standard on this listing

• Faceplate: Standard with faceplate. For flush floor mount without faceplate, specify 3910N

3910 vs. 3910N vs. 3911: Choosing the Correct Version

The base 3910 includes a faceplate and is the correct specification for standard floor installations where the faceplate will sit flush against the finished floor surface. The faceplate provides a clean finished appearance around the floor bore and protects the edge of the drilled hole from chipping or damage.

The 3910N omits the faceplate entirely, which is the correct choice when the installation requires a flush floor mount configuration where no faceplate can protrude above the floor surface. This comes up on polished concrete, stone, or tile floors where a protruding faceplate edge would be a tripping hazard or an aesthetic problem.

The 3911 is the adjustable dust proof strike. It includes a wrench that allows depth adjustment after installation, making it the correct choice when carpet or a threshold is present. If the floor bolt must travel through carpet or clear a threshold before reaching the strike, the fixed depth of the 3910 may cause the bolt to bottom out against the top of the strike rather than seating cleanly. The 3911 adjusts to compensate for this condition.

Browse all Dust Proof Strikes, the complete Flush Bolts and Coordinators catalog, and all Builders Hardware at American Locksets.