119 Connection Thread Tightening Method 5. Face seal fittings: R, NPT, G 1. Tighten fittings with sealant using the proper tightening torques in the table below. 2. Insufficient tightening may cause seal failure, or loosen the threads. 3. Reuse 1) Normally, fittings with a sealant can be reused 6 to 10 times. 2) The seal ring cannot be replaced. Connection thread size (R, NPT, G) Proper tightening torque (N・m) 1/16, 1/8 3 to 5 1/4 8 to 12 3/8 15 to 20 1/2 20 to 25 oD 45° Caution 1. Chamfer dimension for female thread of the connection thread M3, M5, 10-32UNF Confirming to ISO 16030 (air pressure fluid dynamics . connection . ports and stud ends), the chamfer dimensions shown below are recommended. By chamfering as shown in the following table, machining of threads is easier and effective for burr prevention. Chamfer Dimension for Female Thread Connection thread size Chamfer dimension oD (Recommended value) (mm) M3 3.1 to 3.4 M5 5.1 to 5.4 10-32UNF 5.0 to 5.3 Connection Female Thread: Rc, NPT, NPTF Connection Female Thread: G 2) The gasket can be reused 6 to 10 times. It can be replaced easily when it has sustained damage. A broken gasket can be removed by holding it and then turning it in the same direction as loosening the thread. If gasket is difficult to remove, cut it with nippers, etc. In such a case, use caution not to scratch the seat face because the seat face of 45° gasket of fitting is the sealing face. 6. Uni thread fittings 1) First, tighten the threaded portion by hand, then use a proper wrench, which could be suitable for the width across flats of the hexagon body, to tighten it further at a wrench tightening angle shown below. As a reference value for the tightening torque, refer to the table below. Uni thread size Wrench tightening angle after hand-tightening (deg) Tightening torque (N・m) 1/8 30 to 45 3 to 4 1/4 15 to 30 4 to 5 3/8 15 to 30 8 to 9 1/2 15 to 30 14 to 15 Uni thread size Wrench tightening angle after hand-tightening (deg) Tightening torque (N・m) 1/8 30 to 60 3 to 5 1/4 30 to 60 8 to 12 3/8 15 to 45 14 to 16 1/2 15 to 30 20 to 22 45° Counterbore diameter oD3 Seal bearing surface diameter oD2 Rz 25 (Sealing face) Chamfer dimension oD1 Female thread inclination angle: 1° or less 3. Chamfer dimension for female thread of face seal fitting (R, NPT, G) 1) Surface roughness of bearing surface: Rz 25 or less 2) Chamfer dimension: oD1, Seal bearing surface diameter: oD2 (Refer to the table below.) 3) Female thread inclination angle: 1° or less 4) Counterbore diameter when the female thread is counterbored.: oD3 ・ Models with width across flats: Body width across flats x 1.1 or more ・ Models other than hexagon (Hexagon socket head male connector etc.): Body dimensions + 0.2 mm or more * The width across flats and the body dimensions differ depending on the model even when the same thread size is used. Refer to the dimensions in the catalog. 5) If oil content or sealant is sticking to the female thread, this may cause damage of the product. Remove it before piping. Connection thread size Chamfer dimension oD1 mm Seal bearing surface diameter oD2 mm R1/8 10.2 to 10.4 12 or more R1/4 13.6 to 13.8 17 or more R3/8 17.1 to 17.3 21 or more R1/2 21.4 to 21.6 27 or more NPT1/16 8.2 to 8.4 11.11 or more NPT1/8 10.5 to 10.7 12.7 or more NPT1/4 14.1 to 14.3 17.46 or more NPT3/8 17.4 to 17.6 22 or more NPT1/2 21.7 to 21.9 28.7 or more G1/8 10.2 to 10.6 12 or more G1/4 13.6 to 14.0 17 or more G3/8 17.1 to 17.5 21 or more G1/2 21.4 to 21.8 27 or more Caution Chamfer Dimension for Female Thread 45° Rz 12.5 oD * For Uni thread, Rz 12.5 is necessary for sealing at the chamfered part. 2. Chamfer dimension of R and NPT thread with sealant, and Uni thread Connection thread size Chamfer dimension oD (Recommended value) G Rc NPT, NPTF 1/16 . . 8.2 to 8.4 1/8 10.2 to 10.6 10.2 to 10.4 10.5 to 10.7 1/4 13.6 to 14.0 13.6 to 13.8 14.1 to 14.3 3/8 17.1 to 17.5 17.1 to 17.3 17.4 to 17.6 1/2 21.4 to 21.8 21.4 to 21.6 21.7 to 21.9 Fittings & Tubing Precautions 4 Be sure to read this before handling.