Mechanical machining - Import export

Other information Series 14040 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Series 14240 Inner height hi: 62 mm Inner widths Bi: 50 - 400 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Serie 14550 Inner height hi: 70 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 600 mm Pitch: 91 mm E-Chain® with crossbars at every link Series 15050 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Serie 15250 Inner height hi: 86 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Series 14140 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series 14340 Inner height hi: 62 mm Inner widths Bi: 50 - 400 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Serie 14650 Inner height hi: 70 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 600 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series 15150 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Serie 15350 Inner height hi: 86 mm Inner widths Bi: 50 - 400 mm bending radii R: 150 - 600 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series R18840 Inner height hi: 56 mm Inner widths Bi: 75 - 462 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Tube, swivel lid Series R19050 Inner height hi: 70 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 600 mm Pitch: 91 mm E-Tube, swivel lid Series R19850 Inner height hi: 80 mm Inner widths Bi: 75 - 462 mm bending radii R: 200 - 500 mm Pitch: 91 mm E-Tube, swivel lid Assembly tool for E4-series For the practical opening and closing of the E4 series. Big savings in assembly time Assembly tool for E4-series Special design Electrically conductive ESD/ATEX versions on request "Mounted on the side" unsupported application possible High torsionalstiffness Other information Series 14040 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Series 14240 Inner height hi: 62 mm Inner widths Bi: 50 - 400 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Serie 14550 Inner height hi: 70 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 600 mm Pitch: 91 mm E-Chain® with crossbars at every link Series 15050 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Serie 15250 Inner height hi: 86 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Series 14140 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series 14340 Inner height hi: 62 mm Inner widths Bi: 50 - 400 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Serie 14650 Inner height hi: 70 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 600 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series 15150 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Serie 15350 Inner height hi: 86 mm Inner widths Bi: 50 - 400 mm bending radii R: 150 - 600 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series R18840 Inner height hi: 56 mm Inner widths Bi: 75 - 462 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Tube, swivel lid Series R19050 Inner height hi: 70 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 600 mm Pitch: 91 mm E-Tube, swivel lid Series R19850 Inner height hi: 80 mm Inner widths Bi: 75 - 462 mm bending radii R: 200 - 500 mm Pitch: 91 mm E-Tube, swivel lid Assembly tool for E4-series For the practical opening and closing of the E4 series. Big savings in assembly time Assembly tool for E4-series E-Chain® selection aids You can find the right E-Chain® quickly by entering concrete parameters and with the aid of a comparison table. Selection aids Installation instructions Joining, separating and opening of the E-Chain® and E-Tubes. Assembly Instructions Application examples Applications in various industrial sectors and in the igus® test laboratory. E4/light New E4/light version with the proved and tested "tongue and groove" system of the Series E4/4 Low weight Optimized interior-exterior dimensions ratio Cost efficient Manifold interior separation potentials Large accessory kits Thin external links Max. travel distance: 150 - 400 m Typical industrial sectors and applications Machine tools (closed E4/light tubes and open E-Chain®) Material processing Stone cutting machines Woodworking machines General mechanical engineering Vehicles Construction machinery Limited application of long travels Special design Electrically conductive ESD/ATEX versions on request "Mounted on the side" unsupported application possible High torsionalstiffness

Overview of E4.1 benefits Additional information Series E4.21 Inner height hi: 21 mm Inner widths Bi: 30 - 120 mm bending radii R: 38 - 200 mm Pitch: 30.5 mm E-Chain® with crossbars at every link Series E4.28 Inner height hi: 28 mm Inner widths Bi: 40 - 300 mm bending radii R: 55 - 250 mm Pitch: 46 mm E-Chain® with crossbars at every link Series E4.32 Inner height hi: 32 mm Inner widths Bi: 50 - 400 mm bending radii R: 63 - 300 mm Pitch: 56 mm E-Chain® with crossbars at every link Series E4.42 Inner height hi: 42 mm Inner widths Bi: 50 - 400 mm bending radii R: 75 - 350 mm Pitch: 67 mm E-Chain® with crossbars at every link Series E4.56 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Series E4.80 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 1000 mm Pitch: 111 mm E-Chain® with crossbars at every link Series 1640 Inner height hi: 112 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 600 mm Pitch: 143 mm E-Chain® with crossbars at every link E4.112 series Inner height hi: 112 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 1000 mm Pitch: 143 mm E-Chain® with crossbars at every link E4.162 series Inner height hi: 162 mm Inner widths Bi: 200 - 600 mm bending radii R: 250 - 1000 mm Pitch: 200 mm E-Chain® with crossbars at every link Series 800 Inner height hi: 200 mm Inner widths Bi: 200 - 600 mm bending radii R: 325 - 1000 mm Pitch: 250 mm E-Chain® with crossbars at every link Series 840 Inner height hi: 204 mm Inner widths Bi: 100 - 563 mm bending radii R: 325 - 1000 mm Pitch: 250 mm E-Chain® with crossbars at every link Series E4.350 Inner height hi: 350 mm Inner widths Bi: 400 - 800 mm bending radii R: 500 - 1000 mm Pitch: 470 mm E-Chain® with crossbars at every link Series H4.32 Inner height hi: 32 mm Inner widths Bi: 50 - 400 mm bending radii R: 63 - 300 mm Pitch: 56 mm E-Chain® with crossbars at every other link Series H4.42 Inner height hi: 42 mm Inner widths Bi: 50 - 400 mm bending radii R: 75 - 350 mm Pitch: 67 mm E-Chain® with crossbars at every other link Series H4.56 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series H4.80 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 1000 mm Pitch: 111 mm E-Chain® with crossbars at every other link Series H4.112 Inner height hi: 112 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 1000 mm Pitch: 143 mm E-Chain® with crossbars at every other link Series R4.28 Inner height hi: 28 mm Inner widths Bi: 50 - 300 mm bending radii R: 63 - 250 mm Pitch: 46 mm E-Tube, swivel lid Series R4.32 Inner height hi: 32 mm Inner widths Bi: 50 - 300 mm bending radii R: 125 - 300 mm Pitch: 56 mm E-Tube, swivel lid Series R4.42 Inner height hi: 42 mm Inner widths Bi: 50 - 300 mm bending radii R: 125 - 350 mm Pitch: 67 mm E-Tube, swivel lid Series R4.56 Inner height hi: 56 mm Inner widths Bi: 75 - 462 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Tube, swivel lid Series R4.80 Inner height hi: 80 mm Inner widths Bi: 150 - 460 mm bending radii R: 200 - 1000 mm Pitch: 111 mm E-Tube, swivel lid Series R1608 Inner height hi: 112 mm Inner widths Bi: 200 - 400 mm bending radii R: 250 - 600 mm Pitch: 143 mm E-Tube, swivel lid R4.112 series Inner height hi: 112 mm Inner widths Bi: 200 - 400 mm bending radii R: 250 - 1000 mm Pitch: 143 mm E-Tube, swivel lid Assembly tool for E4-series For the practical opening and closing of the E4 series. Big savings in assembly time Assembly tool for E4-series IPA classification -Report IG 1303-640, tested E4.32.10.063.0 41 dB(A) determined at the igus® laboratory, v = 1.8 m/s unsupported ESD classification: Electrically conductive ESD/Atex versions on request System E4.1 proven in long travels e-tubes available as special design with HT material for 850°C hot chips Overview of E4.1 benefits Additional information Series E4.21 Inner height hi: 21 mm Inner widths Bi: 30 - 120 mm bending radii R: 38 - 200 mm Pitch: 30.5 mm E-Chain® with crossbars at every link Series E4.28 Inner height hi: 28 mm Inner widths Bi: 40 - 300 mm bending radii R: 55 - 250 mm Pitch: 46 mm E-Chain® with crossbars at every link Series E4.32 Inner height hi: 32 mm Inner widths Bi: 50 - 400 mm bending radii R: 63 - 300 mm Pitch: 56 mm E-Chain® with crossbars at every link Series E4.42 Inner height hi: 42 mm Inner widths Bi: 50 - 400 mm bending radii R: 75 - 350 mm Pitch: 67 mm E-Chain® with crossbars at every link Series E4.56 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every link Series E4.80 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 1000 mm Pitch: 111 mm E-Chain® with crossbars at every link Series 1640 Inner height hi: 112 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 600 mm Pitch: 143 mm E-Chain® with crossbars at every link E4.112 series Inner height hi: 112 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 1000 mm Pitch: 143 mm E-Chain® with crossbars at every link E4.162 series Inner height hi: 162 mm Inner widths Bi: 200 - 600 mm bending radii R: 250 - 1000 mm Pitch: 200 mm E-Chain® with crossbars at every link Series 800 Inner height hi: 200 mm Inner widths Bi: 200 - 600 mm bending radii R: 325 - 1000 mm Pitch: 250 mm E-Chain® with crossbars at every link Series 840 Inner height hi: 204 mm Inner widths Bi: 100 - 563 mm bending radii R: 325 - 1000 mm Pitch: 250 mm E-Chain® with crossbars at every link Series E4.350 Inner height hi: 350 mm Inner widths Bi: 400 - 800 mm bending radii R: 500 - 1000 mm Pitch: 470 mm E-Chain® with crossbars at every link Series H4.32 Inner height hi: 32 mm Inner widths Bi: 50 - 400 mm bending radii R: 63 - 300 mm Pitch: 56 mm E-Chain® with crossbars at every other link Series H4.42 Inner height hi: 42 mm Inner widths Bi: 50 - 400 mm bending radii R: 75 - 350 mm Pitch: 67 mm E-Chain® with crossbars at every other link Series H4.56 Inner height hi: 56 mm Inner widths Bi: 50 - 600 mm bending radii R: 135 - 500 mm Pitch: 91 mm E-Chain® with crossbars at every other link Series H4.80 Inner height hi: 80 mm Inner widths Bi: 50 - 600 mm bending radii R: 150 - 1000 mm Pitch: 111 mm E-Chain® with crossbars at every other link Series H4.112 Inner height hi: 112 mm Inner widths Bi: 50 - 600 mm bending radii R: 200 - 1000 mm Pitch: 143 mm E-Chain® with crossbars at every other link Series R4.28 Inner height hi: 28 mm Inner widths Bi: 50 - 300 mm bending radii R: 63 - 250 mm Pitch: 46 mm E-Tube, swivel lid Series R4.32 Inner height hi: 32 mm Inner widths Bi: 50 - 300 mm bending radii R: 125 - 300 mm Pitch: 56 mm E-Tube, swivel lid Series R4.42 Inner height hi: 42 mm Inner widths Bi: 50 - 300 mm bending radii R: 125 - 350 mm Pitch: 67 mm E-Tube, swivel lid Series R4.56 Inner height hi: 56 mm Inner widths Bi: 75 - 462 mm bending radii R: 150 - 500 mm Pitch: 91 mm E-Tube, swivel lid Series R4.80 Inner height hi: 80 mm Inner widths Bi: 150 - 460 mm bending radii R: 200 - 1000 mm Pitch: 111 mm E-Tube, swivel lid Series R1608 Inner height hi: 112 mm Inner widths Bi: 200 - 400 mm bending radii R: 250 - 600 mm Pitch: 143 mm E-Tube, swivel lid R4.112 series Inner height hi: 112 mm Inner widths Bi: 200 - 400 mm bending radii R: 250 - 1000 mm Pitch: 143 mm E-Tube, swivel lid Assembly tool for E4-series For the practical opening and closing of the E4 series. Big savings in assembly time Assembly tool for E4-series IPA Classification Report IG 1303-640, tested series E4.32.10.063.0 E-Chain® selection aids You can find the right E-Chain® quickly by entering concrete parameters and with the aid of a comparison table. Selection aids Assembly instruction video Assembly video with accurate description for joining, splitting and opening e-chains® and e-tubes. Installation instructions Application examples Applications in various industrial sectors and in the igus® test laboratory. E 4.1 E4.1-E-Chain® with 4-piece structure Smooth, cable friendly inner surfaces Low noise operation through integrated "brake" on the radial stop dogs Sound dampers as an additional noise-reducing option Wide application range Numerous interior separation options Large accessory kits Widths up to 2000 mm through extension links To open on both sides Max. travel distance: Over 200 m Typical industrial sectors and applications: Krane Indoor Cranes Composting systems Sewage treatment plants Machine tools General mechanical engineering Materials-Handling Technology Refrigeration engineering Construction machinery Wood working Robotics and handling systems IPA classification -Report IG 1303-640, tested E4.32.10.063.0 41 dB(A) determined at the igus® laboratory, v = 1.8 m/s unsupported ESD classification: Electrically conductive ESD/Atex versions on request System E4.1 proven in long travels e-tubes available as special design with HT material for 850°C hot chips

Other information Installation video: Instructions for the opening and closing of the E-Tubes Series R117 Inner height hi: 21 mm Inner widths Bi: 20 - 100 mm bending radii R: 63 - 180 mm Pitch: 30,5 mm E-Tube, snap-open along the inner radius on both sides Series R118 Inner height hi: 21 mm Inner widths Bi: 20 - 100 mm bending radii R: 63 - 180 mm Pitch: 30,5 mm E-Tube, snap-open along the outer radius on both sides Series R157 Inner height hi: 40 mm Inner widths Bi: 40 - 200 mm bending radii R: 100 - 250 mm Pitch: 46 mm E-Tube, snap-open along the inner radius on both sides Series R158 Inner height hi: 40 mm Inner widths Bi: 40 - 200 mm bending radii R: 100 - 250 mm Pitch: 46 mm E-Tube, snap-open along the outer radius on both sides Series R167 Inner height hi: 50 mm Inner widths Bi: 50 - 250 mm bending radii R: 100 - 300 mm Pitch: 58,8 mm E-Tube, snap-open along the inner radius on both sides Series R168 Inner height hi: 50 mm Inner widths Bi: 50 - 250 mm bending radii R: 100 - 300 mm Pitch: 58,8 mm E-Tube, snap-open along the outer radius on both sides iF-Design-Award for Series R117/R118 and Series R68 ESD classification: Electrically conductive ESD/Atex versions on request UL94-V0 Classifications on request E-Tube made of igumid HT: Hot chips (to 850°C) cannot burn into it. Supplied as a special design on request Other information Series R117 Inner height hi: 21 mm Inner widths Bi: 20 - 100 mm bending radii R: 63 - 180 mm Pitch: 30,5 mm E-Tube, snap-open along the inner radius on both sides Series R118 Inner height hi: 21 mm Inner widths Bi: 20 - 100 mm bending radii R: 63 - 180 mm Pitch: 30,5 mm E-Tube, snap-open along the outer radius on both sides Series R157 Inner height hi: 40 mm Inner widths Bi: 40 - 200 mm bending radii R: 100 - 250 mm Pitch: 46 mm E-Tube, snap-open along the inner radius on both sides Series R158 Inner height hi: 40 mm Inner widths Bi: 40 - 200 mm bending radii R: 100 - 250 mm Pitch: 46 mm E-Tube, snap-open along the outer radius on both sides Series R167 Inner height hi: 50 mm Inner widths Bi: 50 - 250 mm bending radii R: 100 - 300 mm Pitch: 58,8 mm E-Tube, snap-open along the inner radius on both sides Series R168 Inner height hi: 50 mm Inner widths Bi: 50 - 250 mm bending radii R: 100 - 300 mm Pitch: 58,8 mm E-Tube, snap-open along the outer radius on both sides Installation video: Instructions for the opening and closing of the E-Tubes E-Chain® selection aids You can find the right E-Chain® quickly by entering concrete parameters and with the aid of a comparison table. Selection aids Installation instructions Joining and separating of the E-Tubes. Assembly Instructions Application examples Applications in various industrial sectors and in the igus® test laboratory. E2 R100 and E2 R Chip protection, swivelable Excellent protection against chips (even hot chips) Rugged and tight Snap-open alternately along inside or outside - Swivelable or removable lid, short installation time Space-saving through good internal/external dimensions ratio Modular interior separation options Double stop dog system for longer service life and long, unsupported lengths Universal KMA mounting brackets with potential for "all-round" fastening Typical industrial sectors and applications Machine tools Timber Processing Machines General mechanical engineering etc In all areas exposed to dirt and chips iF-Design-Award for Series R117/R118 and Series R68 ESD classification: Electrically conductive ESD/Atex versions on request UL94-V0 Classifications on request E-Tube made of igumid HT: Hot chips (to 850°C) cannot burn into it. Supplied as a special design on request

Other information Series 10 Inner height hi: 18 mm Inner widths Bi: 15 - 100 mm bending radii R: 28 - 180 mm Pitch: 30,5 mm E-Chain®, not-to-be-opened Series 11.031 Inner height hi: 23 mm Inner width Bi: 31 mm Bending radii R: 45 - 70 mm Pitch: 30.5 mm E-Chain®, not-to-be-opened Series 11.080 Inner height hi: 28 mm Inner width Bi: 80 mm Bending radius R: 38 mm Pitch: 30.5 mm E-Chain®, not-to-be-opened Series 11.1/11.2 Inner height hi: 41 mm Inner widths Bi: 15 - 25 mm bending radii R: 40 - 100 mm Pitch: 30,5 mm E-Chain®, not-to-be-opened Series 14 Inner height hi: 20 mm Inner widths Bi: 15 - 50 mm bending radii R: 28 - 125 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series B15i Inner height hi: 17 mm Inner widths Bi: 15 - 100 mm bending radii R: 38 - 180 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series B17i Inner height hi: 32 mm Inner widths Bi: 15 - 100 mm bending radii R: 48 - 125 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series F17 Inner height hi: 32 mm Inner height Bi: 15 mm Bending radii R: 48 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series B15 Inner height hi: 17 mm Inner widths Bi: 15 - 100 mm bending radii R: 38 - 180 mm Pitch: 30,5 mm E-Chain®, snap-open outside Series B17 Inner height hi: 32 mm Inner widths Bi: 15 - 100 mm bending radii R: 48 - 125 mm Pitch: 30,5 mm E-Chain®, snap-open outside UL94-V2 classifications Cleanroom class 1 (ISO class 3) Series 10 tested by Dryden Engineering Company, California Special version: Electrically conductive ESD/ATEX versions on request Other information Series 10 Inner height hi: 18 mm Inner widths Bi: 15 - 100 mm bending radii R: 28 - 180 mm Pitch: 30,5 mm E-Chain®, not-to-be-opened Series 11.031 Inner height hi: 23 mm Inner width Bi: 31 mm Bending radii R: 45 - 70 mm Pitch: 30.5 mm E-Chain®, not-to-be-opened Series 11.080 Inner height hi: 28 mm Inner width Bi: 80 mm Bending radius R: 38 mm Pitch: 30.5 mm E-Chain®, not-to-be-opened Series 11.1/11.2 Inner height hi: 41 mm Inner widths Bi: 15 - 25 mm bending radii R: 40 - 100 mm Pitch: 30,5 mm E-Chain®, not-to-be-opened Series 14 Inner height hi: 20 mm Inner widths Bi: 15 - 50 mm bending radii R: 28 - 125 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series B15i Inner height hi: 17 mm Inner widths Bi: 15 - 100 mm bending radii R: 38 - 180 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series B17i Inner height hi: 32 mm Inner widths Bi: 15 - 100 mm bending radii R: 48 - 125 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series F17 Inner height hi: 32 mm Inner height Bi: 15 mm Bending radii R: 48 mm Pitch: 30,5 mm E-Chain®, snap-open inside Series B15 Inner height hi: 17 mm Inner widths Bi: 15 - 100 mm bending radii R: 38 - 180 mm Pitch: 30,5 mm E-Chain®, snap-open outside Series B17 Inner height hi: 32 mm Inner widths Bi: 15 - 100 mm bending radii R: 48 - 125 mm Pitch: 30,5 mm E-Chain®, snap-open outside E-Chain® selection aids You can find the right E-Chain® quickly by entering concrete parameters and with the aid of a comparison table. Selection aids Installation instructions Joining and separating of chain links Assembly Instructions Application examples Applications in various industrial sectors. E2 mini One-/Two-piece E-Chain® Small pitch for silent operation High torsion resistance Double stop system and large pins for long service life Optimized weight/stability ratio Easy to mount Manifold interior separation Typical industrial sectors and applications Construction machinery Handling systems Installation Packaging machines Textile machines Vehicle construction Wood machines Glass machines Machine construction General mechanical engineering etc. UL94-V2 classifications Cleanroom class 1 (ISO class 3) Series 10 tested by Dryden Engineering Company, California Special version: Electrically conductive ESD/ATEX versions on request