DRILLCO 4290 Hex Nut Shank Bridge/Construction Reamer — Heavy-Duty HSS Reaming for Structural Steel
The DRILLCO 4290 Series Hex Nut Shank Bridge/Construction Reamer is a premium-grade High Speed Steel tool engineered for the demanding reaming operations encountered in structural steel fabrication and construction. Designed specifically for enlarging and aligning holes in metal, these reamers feature a hex nut shank for direct use with impact wrenches and power tools that accept impact sockets. The tapered point facilitates entry into misaligned holes, making them an essential tool for ironworkers, structural steel fabricators, and heavy construction contractors. Available in car (shorter) length for thinner or shorter workpieces and bridge (longer) length for standard structural applications, the 4290 series covers a wide range of diameters from 1/2" to 1-9/16".
Technical Specifications
| Specification | Details |
|---|---|
| Brand | DRILLCO |
| Item # (featured SKU) | 429A132 |
| UPC (featured SKU) | 045997096650 |
| Country of Origin | United States |
| Material | Premium grade HSS (High Speed Steel) |
| Flute Type | Spiral flutes |
| Shank Type | Hex nut shank |
| Surface Treatment | Black oxide |
| Point Type | Tapered point |
| Applications | Enlarging holes in metal, aligning misaligned holes in metal, for use in power tools that use impact sockets |
| Series | 4290 |
| Length Style | Car length (shorter) and Bridge length (longer) |
Available Sizes
| Item # | Size | Description |
|---|---|---|
| 429A132 | 1/2" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A136 | 9/16" | Nut Shank Construction Reamer – 4290 |
| 429A140 | 5/8" | Nut Shank Construction Reamer – 4290 |
| 429A144 | 11/16" | Nut Shank Construction Reamer – 4290 |
| 429A148 | 3/4" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A152 | 13/16" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A156 | 7/8" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A160 | 15/16" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A164 | 1" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A204 | 1-1/16" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A208 | 1-1/8" | Hex Nut Construction Reamer – 4290 |
| 429A212 | 1-3/16" | Nut Shank Construction Reamer – 4290 |
| 429A216 | 1-1/4" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A220 | 1-5/16" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A224 | 1-3/8" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A228 | 1-7/16" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A232 | 1-1/2" | Hex Nut Shank Bridge Reamer – 4290 |
| 429A236 | 1-9/16" | Hex Nut Shank Bridge Reamer – 4290 |
The 4290 series distinguishes itself from general-purpose reamers through its hex nut shank design, which allows direct engagement with impact wrenches — eliminating the need for specialized tooling adapters on the job site. The black oxide surface treatment reduces friction and extends tool life compared to uncoated HSS alternatives, while the spiral flute geometry provides faster chip evacuation than straight-flute designs during heavy structural reaming operations.
Key Features & Benefits
Premium Grade HSS Construction
Manufactured from premium grade High Speed Steel, the 4290 reamer delivers the hardness and wear resistance required for repeated heavy-duty reaming in structural steel. HSS tooling maintains its cutting edge integrity through the heat generated in demanding metal fabrication environments, extending tool life and reducing replacement frequency on the job site.
Spiral Flutes for Faster Chip Ejection
The spiral flute design actively evacuates chips away from the cutting zone during operation, reducing heat buildup and preventing chip packing that can cause tool binding or breakage. This translates to faster, cleaner reaming passes and less downtime clearing obstructions in the hole.
Hex Nut Shank for Impact Wrench Compatibility
The hex nut shank is specifically designed for use with impact wrenches and power tools that accept impact sockets, allowing contractors to drive the reamer with the same tools already on the job site. This eliminates the need for a dedicated drill motor or specialized adapter, improving workflow efficiency during structural steel assembly.
Tapered Point for Easy Hole Alignment
The tapered point is engineered to facilitate entry into holes that are out of alignment, a common condition in structural steel fabrication where bolt holes in mating members must be brought into register. This self-starting geometry reduces setup time and allows the reamer to begin correcting misalignment immediately upon engagement.
Black Oxide Surface Treatment for Extended Life
The black oxide finish reduces friction between the tool and workpiece, lowering cutting temperatures and extending the service life of the reamer. This surface treatment is well-suited for the low to medium tensile strength steel materials commonly encountered in structural fabrication and bridge construction.
Car Length Option for Shorter or Thinner Workpieces
In addition to the standard bridge (longer) length, the 4290 series is available in car (shorter) length, providing better rigidity and control when reaming thinner structural members or working in confined spaces. Shorter tooling also reduces deflection, improving hole accuracy in lighter-gauge applications.
Common Applications
Structural Steel Fabrication
Especially adapted for heavy-duty reaming as encountered in the fabrication of structural steel assemblies, where bolt holes must be enlarged or brought into precise alignment before fastener installation.
Bridge Construction
The bridge-length configuration is designed for the extended reach required when reaming through thick structural members and connection plates typical of bridge and heavy civil construction projects.
Misaligned Hole Correction
The tapered point allows the reamer to enter and begin correcting holes that are out of alignment between mating steel members, a critical operation during steel erection when bolt holes in separate fabricated pieces must be brought into register.
Hole Enlargement in Metal
Used to enlarge existing holes in metal to a precise finished diameter, accommodating larger fasteners or correcting undersized holes produced during initial drilling or punching operations.
Impact Wrench-Driven Reaming
The hex nut shank enables use with impact wrenches and power tools that accept impact sockets, making the 4290 series practical for field ironworking operations where dedicated drill motors may not be available.
Compatible Materials
- Metal (structural steel and similar ferrous materials)
Product Documents
Safety Data Summary
Hazard Information
- During normal operation and usage, high speed steel products do not present inhalation, ingestion, or other chemical hazards.
- Operations such as grinding, cutting, machining, burning, and welding may release dusts, fumes, or vapors which may present health hazards if exposure limits are exceeded.
- Excessive inhalation of metallic fumes and dusts may result in irritation of eyes, nose, and throat; symptoms may include metallic taste, dryness and irritation of the throat, chills, and fever persisting 12 to 48 hours.
- Chromium (present 0–5% by weight) is listed as a carcinogen by NTP and OSHA; various forms of dermatitis and inflammation of the upper respiratory tract are associated with chromium exposure.
- Tungsten (present 5–10% by weight): some evidence of pulmonary involvement such as cough.
- Vanadium (present 0–5% by weight): eye and respiratory tract irritant.
- Cobalt dust (from grinding) is reported as the most probable cause of respiratory diseases including occupational asthma and interstitial fibrosis.
- NFPA Hazard Rating: Health 1; Flammability 0; Reactivity 0.
- Fine metal particles produced when ground or sawed can burn; high concentrations in air may present an explosion hazard.
Personal Protective Equipment
- Cloth or leather gloves recommended when contact with dust or mist is likely.
- Wear safety glasses or goggles with side shields; contact lenses should not be worn when handling these materials.
- Hearing protection might be required.
- Always use machine guards and wear safety glasses and protective clothing to prevent injury in the event of tool breakage.
- Use an appropriate NIOSH-approved respirator if airborne dust concentration exceeds the applicable PEL or TLV; all requirements of 29 CFR 1910.134 must be met.
- Use local exhaust ventilation adequate to limit personal exposure to airborne dust to levels not exceeding the PEL or TLV.
Safe Handling
- Perform grinding, cutting, machining, burning, and welding operations in well-ventilated areas.
- Wash hands thoroughly after handling and before eating or smoking; wash exposed skin at the end of the work shift.
- Do not shake clothing, rags, or other items to remove dust — remove dust by washing or vacuuming with appropriate filters.
- Soiled clothing should be laundered separately.
- Store in a dry place in a manner that prevents accidental environmental contamination from traces of industrial lubricants or wetting oils.
- Clean up spills using methods that avoid dust generation such as vacuum (with appropriate filters), wet dust mop, or wet clean up.
- Incompatible materials: strong acids, strong oxidizers.
- Emergency phone number: CHEM-TEL INC 1-800-255-3924.
Frequently Asked Questions
Q: What is the 4290 series reamer designed to do?
A: The 4290 Hex Nut Shank Bridge/Construction Reamer is designed for enlarging holes in metal and aligning misaligned holes in metal, and is especially adapted for heavy-duty reaming as encountered in the fabrication of structural steel assemblies.
Q: What type of power tool is this reamer compatible with?
A: The hex nut shank is designed for use with impact wrenches and power tools that accept impact sockets.
Q: What sizes are available in the 4290 series?
A: The 4290 series is available in 18 sizes ranging from 1/2" (Item# 429A132) through 1-9/16" (Item# 429A236), including 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16", 1", 1-1/16", 1-1/8", 1-3/16", 1-1/4", 1-5/16", 1-3/8", 1-7/16", and 1-1/2".
Q: What material is the reamer made from, and what surface treatment does it have?
A: The 4290 reamer is made from premium grade HSS (High Speed Steel) and features a black oxide surface treatment for extended tool life.
Q: What is the difference between the car length and bridge length versions?
A: Car length is the shorter configuration, suited for shorter or thinner workpieces. Bridge length is the longer configuration, designed for standard structural steel reaming applications.
Q: What flute design does the 4290 use, and why does it matter?
A: The 4290 uses spiral flutes, which provide faster chip ejection and cutting operation compared to straight-flute designs, helping to keep the cutting zone clear and maintain efficient material removal during heavy-duty reaming.