VT-O · Square Full Extension — Veltork telescopic rails

Construction & principle

Series VT-O is a full-extension slide of near-square section, closely related to VT-X but with a box-form intermediate that shields the ball cage. The rigid intermediate allows mounting in either the radial or axial direction with almost the same load capacity.

Standard execution is one-way, the extended length slightly exceeding the closed length. Two-way travel is achieved by removing the end-stop screws — built-in pins keep the slide from separating. On request, special stroke to 130 % of the closed length is available. External end stops are required to arrest a moving load.

shield

Protected ball cage

The near-square box section shields the cage from contamination.

sync_alt

Radial or axial mount

Mount the rigid intermediate either way at practically equal capacity.

open_in_full

Full extension

100 % access to the moving unit; special stroke to 130 % on request.

swap_horiz

One- or two-way

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

Profile & cross-section dimensions

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

Cross-section — VT-O

Extension principle

Cross-section dimensions — all sizes [mm]

Type	Size	A [mm]	B [mm]	E [mm]	Thread	Weight [kg/m]
VT-O	22	22	22	3	M4	2.64
VT-O	28	26	28	1	M5	4.04
VT-O	35	34	35	2	M6	6.1
VT-O	43	44	43	2.5	M8	10.5

Dimension callouts

Aoverall section width (fixed + moving rail)

Boverall section height

Ecorner chamfer

Vmounting thread

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.

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

Envelope per size — will it fit?

Size	Section W × H	Thread
VT-O22	22 × 22 mm	M4
VT-O28	26 × 28 mm	M5
VT-O35	34 × 35 mm	M6
VT-O43	44 × 43 mm	M8

Dimensions are nominal values from the VT-O 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-O22 VT-O28 VT-O35 VT-O43

VT-O22 · 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	472	472	4	0.8
22	370	392	372	372	5	1.0
22	450	462	324	324	6	1.2
22	530	548	272	272	7	1.4
22	610	632	234	234	8	1.6
22	690	702	216	216	9	1.8
22	770	788	190	190	10	2.0

VT-O28 · 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	1244	1074	4	1.2
28	370	380	964	964	5	1.5
28	450	464	786	786	6	1.8
28	530	548	664	664	7	2.1
28	610	633	572	572	8	2.5
28	690	717	504	504	9	2.8
28	770	801	452	452	10	3.1
28	850	866	426	426	11	3.4
28	930	950	388	388	12	3.8
28	1010	1034	356	356	13	4.1
28	1090	1118	328	328	14	4.4
28	1170	1202	304	304	15	4.7

VT-O35 · 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	1334	1120	4	1.8
35	370	406	1044	1044	5	2.3
35	450	494	858	858	6	2.7
35	530	558	788	788	7	3.2
35	610	646	676	676	8	3.7
35	690	734	594	594	9	4.2
35	770	798	558	558	10	4.7
35	850	886	500	500	11	5.2
35	930	974	454	454	12	5.7
35	1010	1038	434	434	13	6.2
35	1090	1126	398	398	14	6.6
35	1170	1214	366	366	15	7.1
35	1250	1278	354	354	16	7.6
35	1330	1366	330	330	17	8.1
35	1410	1454	308	308	18	8.6
35	1490	1518	298	298	19	9.1

VT-O43 · 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	2662	2558	6	4.7
43	530	556	2386	2386	7	5.6
43	610	626	2164	2164	8	6.4
43	690	726	1824	1824	9	7.2
43	770	796	1690	1690	10	8.1
43	850	866	1576	1576	11	8.9
43	930	966	1386	1386	12	9.8
43	1010	1036	1308	1308	13	10.6
43	1090	1106	1238	1238	14	11.4
43	1170	1206	1118	1118	15	12.3
43	1250	1276	1066	1066	16	13.1
43	1330	1376	976	976	17	14.0
43	1410	1446	938	938	18	14.8
43	1490	1516	900	900	19	15.6
43	1570	1586	868	868	20	16.5
43	1650	1686	806	806	21	17.3
43	1730	1756	780	780	22	18.2
43	1810	1856	730	730	23	19.0
43	1890	1926	708	708	24	19.8
43	1970	2026	668	668	25	20.7

Part-number builder

VT-O 22 . 610 . 632 . N

Stroke H is for one-way travel; with stop screws removed the total stroke is 2H.

Examples

VT-O22.610.632
VT-O35.1170.1214.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-O22	15 mm
VT-O28	19 mm
VT-O35	24 mm
VT-O43	30 mm

Field	Meaning
VT-O	Series — square full extension
22	Size (22 / 28 / 35 / 43)
610	Rail length L [mm]
632	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 C₀rad2.7 kN

Available sizes22 · 28 · 35 · 43

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

Contamination-prone environmentsFood & packagingWorkshop drawersVehicle storageOutdoor equipment

Explore the VT range

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

Specify your VT-O — 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.