VT-X · I-Beam Full Extension — Veltork telescopic rails

Construction & principle

Series VT-X reaches 100 % extension using an I-beam intermediate member between two square rail halves. The geometry favours radial (vertical) load at low deflection; axial capacity is lower. In standard form the slide is one-way, the extended length slightly exceeding the closed length.

Two-way travel is obtained by removing the end-stop screws; built-in pins prevent the slide from coming apart. The pins stop the cage and return the intermediate member but are not rated to stop the moving part under load — fit external end stops. Mounting holes are offered countersunk (C) or threaded through-hole (T).

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High radial capacity

The I-beam core carries significant vertical load at minimal deflection.

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Compact square section

Close-to-square envelope gives a compact system at high strength.

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One- or two-way

Standard one-way; two-way by removing the end-stop screws.

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C or T hole types

Countersunk (C, sizes 22–43) or threaded through-hole (T).

Profile & cross-section dimensions

Cross-section of the VT-X profile. Letter callouts (A width, B height, …) correspond to the dimension table — every size in the series is listed.

Cross-section — VT-X

Extension principle

Cross-section dimensions — all sizes [mm]

Type	Size	A [mm]	B [mm]	G [mm]	Thread (C)	Thread (T)	Weight [kg/m]
VT-X	22	22	22	6.5	M4	M4	2.64
VT-X	28	26	28	7.5	M5	M5	4.04
VT-X	35	34	35	10	M6	M6	6.1
VT-X	43	44	43	13.5	M8	M8	10.5
VT-X	63	58	63	10.5	M8	-	20.6

Dimension callouts

Aoverall section width (fixed + moving rail)

Boverall section height

Gmounting-hole axis, measured in from the outer face

Fthread, fixed rail — countersunk execution

Vthread, moving rail — threaded execution

Mounting interface

Where the holes sit along the rail, what thread they carry, and the section envelope of each size — the two checks before you commit an interface.

Mounting-hole pattern — rail, plan view

The first mounting hole sits 25 mm from each end of the rail; the remaining holes follow a constant 80 mm pitch. The hole count for every catalogue length is listed in the specification tables below. Sizes 22–43 are available with countersunk holes (execution C) or threaded through-holes (execution T); size 63 is countersunk only.

Mounting threads: M4 (size 22) · M5 (size 28) · M6 (size 35) · M8 (size 43 / 63). Countersunk DIN 7991 or cheese-head DIN 7984.

Envelope per size — will it fit?

Size	Section W × H	Thread
VT-X22	22 × 22 mm	M4
VT-X28	26 × 28 mm	M5
VT-X35	34 × 35 mm	M6
VT-X43	44 × 43 mm	M8
VT-X63	58 × 63 mm	M8

Dimensions are nominal values from the VT-X engineering catalogue, in millimetres. For a custom hole pattern, length or finish, send us the interface and we return a drawing. Confirm against the released drawing or 3D model before machining mating parts.

Technical parameters & dimensions

Load capacity is per pair of rails.

VT-X22 VT-X28 VT-X35 VT-X43 VT-X63

VT-X22 · 9 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	No. of holes	Weight per rail [kg]
22	130	152	238	166	2	0.3
22	210	222	562	392	3	0.6
22	290	308	780	546	4	0.8
22	370	392	1002	526	5	1.0
22	450	462	1348	460	6	1.2
22	530	548	1142	386	7	1.4
22	610	632	988	334	8	1.6
22	690	702	906	306	9	1.8
22	770	788	802	270	10	2.0

VT-X28 · 14 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	No. of holes	Weight per rail [kg]
28	130	148	470	328	2	0.5
28	210	232	864	604	3	0.8
28	290	296	1534	1074	4	1.2
28	370	380	1936	942	5	1.5
28	450	464	2338	770	6	1.8
28	530	548	2214	650	7	2.1
28	610	633	1910	560	8	2.5
28	690	717	1684	494	9	2.8
28	770	801	1506	442	10	3.1
28	850	866	1420	416	11	3.4
28	930	950	1292	378	12	3.8
28	1010	1034	1184	348	13	4.1
28	1090	1118	1094	320	14	4.4
28	1170	1202	1016	298	15	4.7

VT-X35 · 17 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	No. of holes	Weight per rail [kg]
35	210	254	804	562	3	1.3
35	290	318	1600	1120	4	1.8
35	370	406	2050	1436	5	2.3
35	450	494	2500	1586	6	2.7
35	530	558	3370	1456	7	3.2
35	610	646	3816	1252	8	3.7
35	690	734	3378	1096	9	4.2
35	770	798	3182	1032	10	4.7
35	850	886	2850	926	11	5.2
35	930	974	2582	838	12	5.7
35	1010	1038	2466	800	13	6.2
35	1090	1126	2262	734	14	6.6
35	1170	1214	2090	678	15	7.1
35	1250	1278	2012	654	16	7.6
35	1330	1366	1874	608	17	8.1
35	1410	1454	1754	570	18	8.6
35	1490	1518	1700	552	19	9.1

VT-X43 · 23 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	No. of holes	Weight per rail [kg]
43	210	246	1210	848	3	2.2
43	290	316	2228	1560	4	3.0
43	370	416	2600	1820	5	3.9
43	450	486	3656	2558	6	4.7
43	530	556	4750	2868	7	5.6
43	610	626	5868	2600	8	6.4
43	690	726	6182	2192	9	7.2
43	770	796	6110	2032	10	8.1
43	850	866	5694	1892	11	8.9
43	930	966	5012	1666	12	9.8
43	1010	1036	4728	1572	13	10.6
43	1090	1106	4476	1488	14	11.4
43	1170	1206	4044	1344	15	12.3
43	1250	1276	3856	1282	16	13.1
43	1330	1376	3532	1174	17	14.0
43	1410	1446	3388	1126	18	14.8
43	1490	1516	3256	1082	19	15.6
43	1570	1586	3134	1042	20	16.5
43	1650	1686	2916	970	21	17.3
43	1730	1756	2818	936	22	18.2
43	1810	1856	2640	878	23	19.0
43	1890	1926	2560	850	24	19.8
43	1970	2026	2412	802	25	20.7

VT-X63 · 18 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	No. of holes	Weight per rail [kg]
63	610	666	8180	5726	8	12.6
63	690	746	9718	6124	9	14.2
63	770	826	11270	5568	10	15.9
63	850	906	12830	5106	11	17.5
63	930	986	14396	4714	12	19.2
63	1010	1066	13770	4378	13	20.8
63	1090	1146	12854	4086	14	22.5
63	1170	1226	12052	3832	15	24.1
63	1250	1306	11344	3606	16	25.8
63	1330	1386	10714	3406	17	27.4
63	1410	1466	10152	3228	18	29.0
63	1490	1546	9644	3066	19	30.7
63	1570	1626	9186	2920	20	32.3
63	1650	1706	8768	2788	21	34.0
63	1730	1786	8388	2666	22	35.6
63	1810	1866	8038	2556	23	37.3
63	1890	1946	7718	2454	24	38.9
63	1970	2026	7420	2360	25	40.6

Part-number builder

VT-X C . 28 . 930 . 950 . N

C-holes for sizes 22–43; T-threads M4 (22) · M5 (28) · M6 (35) · M8 (43). Size 63 uses M8 fastening.

Examples

VT-X43C.930.966
VT-X28T.690.358.N

Non-standard stroke steps

Any deviation from the catalogue stroke must be a multiple of the step below (set by the ball-cage pitch); a changed stroke affects the rated capacity.

Size	Stroke step
VT-X22	15 mm
VT-X28	19 mm
VT-X35	24 mm
VT-X43	30 mm
VT-X63	40 mm

Field	Meaning
VT-X	Series — I-beam full extension
C / T	Hole type: C = countersunk · T = threaded through-hole
28	Size (22 / 28 / 35 / 43 / 63)
930	Rail length L [mm]
950	Stroke H [mm] (catalogue, or if non-standard)
N	Additional coating if ≠ standard ISO 2081 zinc

Build your part number & request a price

Open the inquiry builder to pick size & length from the live catalogue, assemble the code automatically and send it for a quote.

tune Not sure? Configurator

Technical data

Extension100 %

Load basisper pair of rails

Peak C₀rad14.4 kN

Available sizes22 · 28 · 35 · 43 · 63

Max rail length1 970 mm

Operating temperature−20 … +170 °C

Max working speed≤ 0.8 m/s (derates with length) · max accel 1.2 m/s²

MaterialCF53 · hardened raceways

RacewaysInduction-hardened raceways

BallsCarbon-steel balls (stainless on request)

Surface coatingsZinc per ISO 2081 (standard) · zinc-nickel · nickel · E-coat on request

LubricationMedium lithium grease; re-lube every 100 km or 6 months. FDA, cleanroom, marine & temperature greases on request.

Clearance / preloadG1 increased clearance · standard zero-clearance · K1 increased preload

FasteningCountersunk DIN 7991 or cheese-head DIN 7984. Torque (10.9): 22→3, 28→6, 35→10, 43→25, 63→30 N·m.

function Selection & sizing

Rated loads are static C₀ values, applied at the centre of the moving member in the fully extended position. Check against a static safety factor S₀ and verify deflection before specifying.

Static safety factor S₀

1.5 smooth · 1.5–2 normal · 2–3.5 shock & vibration. Keep P / C₀ ≤ 1 / S₀.

Deflection

f = (q / t) · P [mm]

q = travel coefficient · t = model coefficient · P = central load.

Typical applications

Machine buildingAutomation cellsPull-out traysInspection drawersVehicle equipment

Explore the VT range

VT-LLinear guidearrow_forward VT-PPartial extensionarrow_forward VT-SSlim full extensionarrow_forward VT-OSquare full extensionarrow_forward VT-HHeavy-duty full ext.arrow_forward

Specify your VT-X — custom length, hole pattern or finish.

Configure the exact model and send it for a quote, or let the configurator find the right series first. Our team returns a part number, deflection estimate and 3D model — prototypes in under 14 days.