Lock sets ensure accurate alignment between the two halves of a mold. The Lock Set feature creates a side lock or an interlock.
The lock set system consists of male and female pieces that align with a close fit. Use straight locks when delicate shut offs protrude from one half of the mold to the other. Otherwise, use tapered interlocks. The two types of lock sets are the side lock and the interlock.
The lock set system consists of a male and female piece that align with a close fit. Use straight locks when delicate shut-offs protrude from one half of the mold to the other. When shut-offs are not an issue, you can use tapered interlocks. The two types of lock sets are the Side Lock and the Interlock.
Side Lock
Side locks are machined on the centerline axis, both vertically and horizontally on the outside of the mold. Lock pockets are machined with both halves of the mold clamped together to ensure parallel location. The following types of side locks are typical:
- The General side lock provides positive alignment for molds with interlocking cavities and cores.
- The X series side lock provides positive alignment between three adjacent plates when the mold has two parting line openings. This design can be used to provide close alignment for interlock cavities and cores in stripper plate or floating plate type molds.
- The Self-lubricating side lock has graphite plugs that provide constant lubrication to reduce maintenance and contamination from grease lines.
Interlock
In addition to aligning mold halves, interlocks lock the core and cavities. The two types of interlocks are the round taper and the taper bar. Tapered interlocks provide positive metal-to-metal mold registry to align mold halves, mold plates, or individual cavities and cores. They maintain proper alignment, and permit thermal expansion between the mold halves. Ensure that male and female mounting pockets are accurately aligned, flat, and parallel to the parting line.

Figure 1. Taper bar interlock
Figure 2. Round taper interlock