As of Q1 2026, HDH Instruments now provides large diameter pull boring services for long, cylindrical components with hole sizes exceeding (>10”) what our traditional pull boring equipment could previously achieve! Our work focuses on accuracy across extended lengths, where alignment and straightness directly affect performance.
We support industries such as oil and gas, aerospace, and heavy manufacturing, where internal precision is critical. With the right equipment and process control, we deliver dependable results across a wide range of materials and part sizes.
What is Large Diameter Boring?
Large diameter boring is used to enlarge and finish the internal diameter of an existing tube. It is commonly required for components that must maintain consistent internal dimensions over long distances. In some cases, the bored ID may serve as the finished dimension, but more often, the bored ID is further refined for tolerance and/or finish through our large diameter honing capabilities.
In this process, the cutting tool is pulled through the part rather than pushed. This improves stability during machining and helps control deflection, especially in long tubular components. The result is a straighter more consistent internal diameter across the full length
At HDH, our large diameter boring services are built around maintaining uniformity from end to end. The goal is simple: consistent bore size, controlled straightness, and a finish that supports the next stage of machining or final use.
Capacity and Capabilities
Diameter and Length Range
- Internal diameters from 6.50” to 20.00”
- Depths of cut up to 1.75” diameter per pass
- Lengths up to 35 feet
Tolerance and Precision
- Standard Tolerance of .060”
- Straightness control across long bores
Material Capability
We machine a wide range of materials, including:
- Carbon steel
- Stainless steel
- Titanium
- Nickel-based alloys such as Inconel and Hastelloy
Boring Methods and Process
HDH applies multiple internal machining methods depending on the application requirements:
- Push boring for standard configurations
- Large diameter pull boring for long-length precision work
- Custom approaches based on material and geometry
Each project is evaluated to select the most effective method. This allows us to maintain accuracy and consistency across the full length of the bore.
Applications and Industries
Our large diameter boring services are used across industries where internal precision directly affects performance.
In oil and gas, this includes tubing, casing modifications, and downhole components. In aerospace and defense, it applies to structural and precision cylindrical parts. Industrial applications include pressure vessels and heavy tubular components used in demanding environments.
These applications require accuracy across the full length of the part, which is where our capabilities are focused.
Quality and Inspection
Inspection is performed throughout the process to confirm that each part meets its specifications. This includes checking internal diameter, verifying straightness, and reviewing surface finish.
Maintaining consistency across the full length of the bore is a key part of our quality approach. This is especially important for components used in high-performance or high-pressure environments.
Advantages of Large Diameter Pull Boring
Large diameter pull boring offers key advantages for long components:
- Improved bore straightness over extended lengths
- Reduced tool deflection during machining
- Consistent internal diameter from end to end
- Better surface finish for finishing operations
This method is especially effective for parts with high length-to-diameter ratios.
Request a Quote
If your project requires large diameter boring, HDH Instruments can support your specifications.
Reach out to discuss your part requirements, material, and delivery timeline.
