MTWS™ Mass Timber Washer Strap
Product Details
Simpson Strong-Tie® tested and load-rated tension straps and fasteners are designed to minimize cost and maximize speed and precision — while providing the strength, versatility and reliability you depend on. The MTWS48 strap utilizes MTW45-8 washers and Strong-Drive® SDCF Timber-CF (SDCF) fully-threaded countersunk-head screws. The combination provides a tension strap with high strength and stiffness that can be used in a variety of CLT diaphragm and wall applications. The MTWS48 is a 7-gauge high-capacity strap specifically designed to carry tension across a CLT floor or wall panel joint. The MTWS48 can also be used to attach CLT panels to steel attachment points when paired with a welded connection (designed by others).
Key Features
- High capacity reduces the need for expensive shop-fabricated steel plates
- Use of inclined SDCF screws and MTW45-8 washers reduces the number of fasteners needed to achieve the load
- Strap can be used for either CLT panel-to-panel connection or CLT panel-to-steel connection
Material
- 7 gauge (ASTM A653 Grade 33)
Finish
- Galvanized
Installation
- Install optional fasteners in diamond holes to hold strap in desired location
- Orient washers so the screws point away from the centerline of the strap and toward the end of the strap
- Install inner fasteners first and work towards the ends of the strap
- Reference engineering letter L-F-MTINSTALL for additional fastener installation information
- Use all specified fasteners and washers
Options
- Multiple combinations of strap width and fastener length are available
- Full straps may be used to connect CLT panels together
- Full straps may be cut into half straps; these half straps may be used to connect CLT panels to steel attachment points (designed by others)
Related Literature
Product Information Table
| Model No. | Ga. | W (in.) | L (in.) | Coating/Material | Packaging Qty. |
|---|---|---|---|---|---|
| MTWS48-5.5 | 7 | 5 7/16 | 47 5/8 | Zinc Galvanized, G90 | 1 |
| MTWS48-8 | 7 | 8 1/16 | 47 5/8 | Zinc Galvanized, G90 | 1 |
Load Tables
Allowable Tension Loads
| Model No. | Ga. | Dimensions (in.) | CLT Layup (min.) | Fasteners (Total) | Allowable Tension (lb.) (160) | |
|---|---|---|---|---|---|---|
| W | L | |||||
| MTWS48-5.5 | 7 | 5 7/16 | 47 5/8 | Three-Ply | (24) SDCF22512 | 11,160 |
| MTWS48-8 | 8 1/16 | (36) SDCF22512 | 16,740 | |||
| MTWS48-5.5 | 5 7/16 | Five-Ply | (24) SDCF22858 | 18,655 | ||
| MTWS48-8 | 8 1/16 | (36) SDCF22858 | 27,600 | |||
- The allowable loads are based on the use of cross-laminated timber (CLT) grades E1-E5 and V1-V5 material conforming to APA PRG-320. The allowable shear load applies to CLT with specific gravity of 0.42 or better and MPP with equivalent specific gravity.
- Allowable loads have been increased for wind or seismic loading with no further increase allowed; reduce where other loads govern.
- When predrilling is used, predrill diameter is 3/16" maximum.
- Use all specified fasteners and washers. Use half of the required fasteners in each member being connected to achieve the listed loads.
- Tension loads apply for uplift when installed vertically.
- Fasteners: SDCF22512 and SDCF22858 = 0.315" OD by 5 1/2" long and 8 5/8" long Strong-Drive SDCF TIMBER-CF screw, respectively.
- Tabulated values are applicable for parallel and perpendicular to the outer layer of CLT.
- CLT panel thickness shall be adequate to accommodate full fastener length.
Code Reports & Compliance
Drawings
| DWG | DXF | RFA | IFC | SAT | |||
|---|---|---|---|---|---|---|---|
