The Renold DL series dual-lead wo←★ δrm gear consists of two≠Ω€ leads. One tooth side of the worm thre✘©&ad and the mating side of the tooth α>are manufactured with one lead, whilΩ₩≥‍e the other tooth side an‍εd the mating side of t↕£↕he tooth are manufactured with a slig ∞↕htly different lead.

In the case of worms, this has the efε€fect of creating worm thr±ε eads, which increase•φ✘ in thickness from one end of the worm ₹♠≈ to the other.

Therefore, if the worm β✘‌<moves axially as it enga→→ges with the worm gear, the backlas‌♥h between the worm pairs can "‍be adjusted to the desired amoun×>δ÷t.

In practice, gears are made such thaδ>•t the initial backlash is achieved a•σ↔t a distance relative to the d×♣atum plane on the worm. Then, du∞←ring the life of the gear, t§≥☆±he worm can be adjusted from that ©‍point as needed.

The DL series of dual-lead wo♣​rm gears offers a number of adva∞וntages for split worm gear de§φ÷‌signs. It provides a kinematically cor→€rect gear that can o★×¥perate in either direction of r$∞otation and its backlash c<βan be infinitely adjusted ¥≥∏from the maximum acceptable value t≈"λ£o zero.

Precision double-lead clearance $'→≈adjustable worm gears are widely ε "used in rotary tables, tool dri→↕≈§ves and machine tool✔± positioning mechanis€®ε£ms