In the structural bolting industry, a DTI washer cut sheet is an essential document for submittals, project approvals, and accurate procurement. Whether you are reviewing technical specifications or preparing for a rigorous receiving inspection, understanding engineering drawings ensures you select the correct component. Precision is paramount, which is why engineering teams rely on the FULLERKREG DTI washer collection for certified, specification-compliant direct tension indicators. For detailed submittal packages, material test reports, or custom cut sheet requests, our technical team is ready to assist. You can reach out to us directly at sales@fullerkr.com to ensure your project's fastening requirements are met with absolute certainty.
What Is a DTI Washer Cut Sheet?
- Submittal review: Provides engineers and architects with the documented proof that the proposed component meets project standards.
- Procurement: Gives purchasing agents exact part numbers, materials, and dimensional specifications to avoid ordering errors.
- Receiving inspection: Acts as the primary reference document for quality control teams to verify incoming shipments against required dimensions.
- Field troubleshooting: Offers site supervisors crucial data on protrusion heights and compression limits when calibrating installation tools.
How to Read a DTI Washer Engineering Drawing
Plan View
The plan view provides a top-down look at the washer. Key dimensions include the O.D. (Outside Diameter), which ensures the washer will fit within the joint without interference, and the I.D. (Inside Diameter), which must clear the bolt threads while supporting the head or nut. It also details the Protrusion Pattern—the number and spacing of the bumps—and any specific Notches or Reliefs designed for tool clearance or identification.
Section View
The section view cuts through the washer to reveal its vertical profile. It highlights T (Thickness), the base material thickness essential for load distribution. You will also find the Bump Height (the uncompressed protrusion height) and the Overall Height, which is critical for determining the required grip length of the bolting assembly.
Why These Dimensions Matter
| Dimension | Specification Risk if Wrong | Field Consequence |
|---|---|---|
| OD too large | Interference with adjacent structural members | Washer won't seat properly; joint cannot be assembled |
| OD too small | Insufficient bearing surface area | Excessive bearing stress leading to embedment or yielding |
| ID too large | Lack of support under the bolt head or nut | Washer may collapse into the hole; inaccurate tensioning |
| ID too small | Binding against the bolt shank or threads | Washer cannot be installed over the bolt |
| T too thin | Inadequate load distribution | Washer deformation and loss of preload over time |
| Bump height incorrect | Improper gap compression ratio | False tension readings; joint may be under- or over-tensioned |
DTI Washer Grade Selection
Grade 325 (ASTM F959 Type 325)
Designed for use with A325 or F1852 structural bolts, these DTIs are engineered for 120 ksi applications commonly found in commercial buildings and standard structural steel framing.
Grade 490 (ASTM F959 Type 490)
Manufactured for use with A490 or F2280 high-strength bolts, these washers are built for 150 ksi applications, including bridges, heavy industrial facilities, and dynamic load environments.
H8 / H10 (EN 14399-9)
These are the metric equivalents used in European EN 1090 compliant structures, with H10 designed for higher preloading forces compared to H8.
The DTI washer grade must always match or exceed the bolt grade.
DTI Washer Finish: Plain vs. Galvanized
Plain Finish
- Appearance: Bare steel, typically lightly oiled.
- Corrosion resistance: Low; prone to rust if exposed to elements.
- Friction: Consistent and predictable baseline friction.
- Cost: Most economical option.
- Best for: Indoor, climate-controlled environments or assemblies that will be fully painted after installation.
Galvanized Finish
- Appearance: Dull, matte gray metallic coating.
- Corrosion resistance: Excellent; protects against severe environmental exposure.
- Friction: Requires specific lubrication (often dyed) to prevent galling.
- Cost: Higher initial cost due to the coating process.
- Best for: Outdoor applications, bridges, and corrosive industrial environments.
Galvanizing Method Matters
- Mechanically Galvanized (ASTM B695): The preferred method for DTIs, providing uniform coating thickness without the risk of heat altering the washer's calibrated compression properties.
- Hot-Dip Galvanized (ASTM A153): Generally avoided for DTIs due to the high heat of the zinc bath, which can anneal the heat-treated protrusions and cause inconsistent tension indication. For expert guidance on finish selection, contact sales@fullerkr.com.
How to Request a DTI Washer Cut Sheet
When preparing submittals, request the following elements from your supplier:
- Full engineering drawing (Plan and Section views)
- Comprehensive dimension table with tolerances
- Material specification and heat treatment details
- Standard compliance statement (e.g., ASTM F959, EN 14399-9)
- Specific grade designation (e.g., Type 325, Type 490)
- Surface finish specification
- Compression load data and gap requirements
- Feeler gauge thickness recommendations
- Marking diagram showing manufacturer ID and lot traceability
Digital Cut Sheets vs. Printed Catalogs
- Searchability: Digital sheets allow engineers to instantly find specific part numbers or dimensions.
- Accuracy: Online specs are updated in real-time, eliminating the risk of using obsolete data.
- Speed: PDF cut sheets can be immediately downloaded and attached to digital submittal packages.
- Revision control: Digital documents ensure you are always viewing the latest engineering revisions. Explore our up-to-date specs at the FULLERKREG DTI washer collection.
FAQ
-
What does a DTI washer cut sheet show?
It shows detailed engineering drawings, exact dimensions, material properties, load requirements, and compliance standards necessary for project approval. -
What is the OD and ID of a DTI washer?
The OD (Outside Diameter) and ID (Inside Diameter) vary by bolt size but are strictly calibrated to ensure proper seating and clearance without interfering with the joint. -
How thick is a DTI washer?
Thickness depends on the nominal bolt diameter and grade, engineered specifically to distribute the high preloading forces without yielding. -
Should I choose plain or galvanized DTI washers?
Choose plain for indoor/painted applications and mechanically galvanized for outdoor or corrosive environments. -
What happens if I use the wrong grade DTI washer?
Using a lower grade washer than the bolt can cause the protrusions to flatten prematurely, resulting in a dangerously under-tensioned connection. -
Where can I get a DTI washer cut sheet with full engineering drawings?
You can access complete technical data and request customized cut sheets through the FULLERKREG DTI washer collection or by emailing our engineering team at sales@fullerkr.com.
Conclusion
Understanding how to read a DTI washer cut sheet empowers you to make informed, specification-compliant procurement decisions. FULLERKREG provides the transparent technical data and high-quality components necessary for your most critical structural connections.
Get Your FULLERKREG DTI Washers Here
Email us at: sales@fullerkr.com