Challenge
During an engineering review of a customer’s facility, Field inquired about the assembly process of one of their most popular tools. During a ‘Fit, Form and Function’ analysis of the tool back in the Field lab, cost saving opportunities were immediately identified.
The original fastener design was flawed and called for large thread angles measured at 60 degrees. The extreme angle caused the boss to stress and crack—a quality issue that was not easily detected. In addition, a round shank in the original design was causing hoop stresses on the plastic boss, preventing the material from relieving stresses. This part was a proprietary design, and suitable alternatives were difficult to find from alternative suppliers.
Solution
The Field team created a new design that utilized a tri-roundular fastener with thinner, 48-degree thread design. This thinner thread angle reduced stresses on the plastic components. To further save costs, the fastener chosen had a twin lead thread design. With two threads starting 180 degrees apart, this fastener could be installed in nearly half the time. The tri-round design also allowed the fastener to drive at a lower torque value.
Once driven, the plastic was conditioned to micro-relax into the low points on the fastener, thus increasing the resistance to loosening. In addition to providing test reports outlining the solution and cost savings, Field also recommended seating torques and other technical details to maximize the fastener performance and improve product quality.
Results
Field recommended a holistic solution for this product which included product design review, supplier sourcing review and a torque application review. Field’s recommendations yielded significant cost savings and results for our customer:
- Increased Sourcing Capabilities
- Cost Reduction = 40% Piece Price Reduction
- Supplier Consolidation
- Decreased Assembly Time
- Annual Cost Savings With Field: $34,148