MTWS Mass Timber Washer Strap
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).
- 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
- 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-SDCFCPIN for additional fastener installation information
- Use all specified fasteners and washers
- 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)
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|
|Model No.||Ga.||Dimensions (in.)||CLT Layup (min.)||Fasteners (Total)||Allowable Tension (lb.) (160)|
|MTWS48-5.5||7||5 7/16||47 5/8||Three-Ply||(24) SDCF22512||10,060|
|MTWS48-8||8 1/16||(36) SDCF22512||15,090|
|MTWS48-5.5||5 7/16||Five-Ply||(24) SDCF22858||17,885|
|MTWS48-8||8 1/16||(36) SDCF22858||26,825|
- The allowable loads are based on the use of cross–laminated timber (CLT) grades E1–E4 and V1–V4 material conforming to APA PRG–320.
- Allowable loads have been increased for wind or seismic loading with no further increase allowed; reduce where other loads govern.
- Predrilling is typically not required. 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 = 0.230″ shank diameter x 5 1/2″ long and 8 5/8″ long Strong–Drive SDCF TIMBER–CF screw, respectively.
- CLT panel minimum thickness is: three–ply = 4.125″; five–ply = 6.875″.
- Tabulated values are applicable for parallel and perpendicular to the outer layer of CLT.
Code Reports & Compliance