sinoboltco Precision Shoulder Screws | Hex Socket Knurled Head, De9 Tolerance, Carbon Steel Grade 10.9 & Stainless Steel A2-50 | Model sndp000001

The sinoboltco sndp000001 series precision shoulder screws (also known as stripper bolts) are heavy-duty engineering components designed for high-accuracy guiding, pivoting, and alignment applications. Unlike standard fastening bolts, the center shaft is ground to an exacting De9 tolerance class to serve as a load-bearing linear shaft or rotational pivot axis, minimizing mechanical play and vibration in high-cycle machinery.

Premium Engineering & Structural Integrity

Material Grades for Heavy Industry: Manufactured in Carbon Steel Grade 10.9 (quenched and tempered to 33-38 HRC surface hardness for exceptional shear strength) or Stainless Steel A2-50 for superior anti-corrosive performance in marine and food-processing environments.

Advanced Head Design: Features an integrated knurled outer head providing maximum tactile grip during manual pre-tightening, backed by a precision-broached internal hex socket (Drive B) to accept standard hex keys for high-torque final clamping.

Under-Head and Thread Relief: Incorporates a precise 2.5mm max. undercut relief zone with specific relief depth (max T) at the thread-to-shoulder transition. This structural design ensures flush seating against the mating plate, eliminating stress concentration points.

Comprehensive Metric Range: Available in standard shoulder diameters (D) from 4mm to 20mm, mating with standard metric threads (M) from M2.5 up to M16.

Industrial Applications

Stamping Dies & Mold Components: Acting as high-tensile stripper bolts for stripper plate spring retention.

Automation & Robotics: Precision pivot joints, linkage arms, and linear guide shafts.

CNC Machine Tools: Retaining components requiring controlled sliding or rotational clearance.

Product Advantages

Zero-Wobble Fitment: The precision-ground shoulder meets exact De9 limits (e.g., -0.020 to -0.050mm for Φ 4-Φ 5.5), preventing concentricity displacement.

High Shear & Wear Resistance: The 10.9 grade carbon steel variant undergoes rigorous induction hardening to 33-38 HRC, resisting structural deformation under massive shock loads.

Flush Seating Design: The engineered thread relief groove ensures the shoulder seats perfectly square against the mounting surface every single time.

Optimized Torque Control: Deep-broached inner hex sockets prevent tool cam-out, allowing engineers to apply full rated torque.

Product Features