VT-P · Partial Extension — Veltork telescopic rails

Construction & principle

Series VT-P is a partial-extension telescopic slide: the outer rail fastens to the supporting structure while the inner carriage extends on bearing balls — typically 50–60 % of the overall length. When integrated into a load-bearing structure it becomes extremely rigid.

Because it does not carry an intermediate member, deflection is governed almost entirely by the rigidity of the mating structure. Removing the stop screw converts the slide to two-way travel. It carries radial and axial loads plus moments in all principal directions.

weight

Highest telescopic load

Hardened raceways and a stiff two-part build give the highest capacity of the telescopic range.

compress

Compact & rigid

Minimal section for the load — ideal for confined, high-stiffness mountings.

swap_horiz

One- or two-way travel

Remove the stop screw to allow travel in both directions.

bolt

Shock & crash rated

Designed for intensive cycling, shock loads and crash-test duty.

Profile & cross-section dimensions

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

Cross-section — VT-P

Extension principle

Cross-section dimensions — all sizes [mm]

Size	A [mm]	A₁ [mm]	B [mm]	J [mm]	G [mm]	Thread	Corner
22	11	10.25	22	11.3	6.5	M4	R3
28	13	12.25	28	15	7.5	M5	R1
35	17	16	35	15.8	10	M6	R2
43	22	21	43	23	13.5	M8	R2.5
63	29	28	63	29.3	10.5	M8	2×45°

Dimension callouts

Aoverall section width

A₁inner width — from the same outer face as A, stopping 0.75–1 mm short of the opposite face

Boverall section height

Jraceway span (distance between the two ball-row centres)

Gmounting-hole axis, measured in from the outer face

Threadmounting thread in outer rail and inner slider

Cornercorner radius / chamfer of the outer profile

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 / 63). Countersunk DIN 7991 or cheese-head DIN 7984.

Envelope per size — will it fit?

Size	Section W × H	Thread
VT-P22	11 × 22 mm	M4
VT-P28	13 × 28 mm	M5
VT-P35	17 × 35 mm	M6
VT-P43	22 × 43 mm	M8
VT-P63	29 × 63 mm	M8

Dimensions are nominal values from the VT-P 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 & moments are per pair of rails (Mx* is per single rail).

VT-P22 VT-P28 VT-P35 VT-P43 VT-P63

VT-P22 · 9 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	Mx* [Nm]	My [Nm]	Mz [Nm]	No. of holes	Weight per rail [kg]
22	130	76	626	438	5.7	20	30	2	0.2
22	210	111	1430	1002	10.7	72	102	3	0.3
22	290	154	1988	1392	14.9	138	198	4	0.4
22	370	196	2556	1790	19	226	324	5	0.5
22	450	231	3402	2380	24	360	516	6	0.6
22	530	274	3958	2770	28.2	496	710	7	0.7
22	610	316	4524	3168	32.3	654	934	8	0.8
22	690	351	5378	3764	37.3	872	1246	9	0.9
22	770	394	5934	4154	41.5	1078	1538	10	1

VT-P28 · 14 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	Mx* [Nm]	My [Nm]	Mz [Nm]	No. of holes	Weight per rail [kg]
28	130	74	1226	858	15.3	40	56	2	0.3
28	210	116	2232	1562	26.1	114	164	3	0.4
28	290	148	3868	2708	39.6	264	376	4	0.6
28	370	190	4890	3422	50.4	426	610	5	0.7
28	450	232	5910	4138	61.2	628	898	6	0.9
28	530	274	6932	4852	72	870	1242	7	1.1
28	610	316	7952	5566	82.8	1150	1642	8	1.2
28	690	358	8974	6282	93.6	1470	2100	9	1.4
28	770	400	9994	6996	104.4	1828	2612	10	1.6
28	850	433	11656	8160	117.9	2330	3330	11	1.7
28	930	475	12676	8872	128.7	2778	3968	12	1.9
28	1010	517	13696	9586	139.5	3262	4660	13	2
28	1090	559	14716	10300	150.3	3788	5410	14	2.2
28	1170	601	15736	11014	161.1	4350	6216	15	2.4

VT-P35 · 17 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	Mx* [Nm]	My [Nm]	Mz [Nm]	No. of holes	Weight per rail [kg]
35	210	127	2130	1492	29.4	114	164	3	0.6
35	290	159	4120	2884	46.9	292	416	4	0.9
35	370	203	5276	3694	59.9	476	680	5	1.1
35	450	247	6434	4504	73	708	1010	6	1.4
35	530	279	8564	5994	90.4	1086	1550	7	1.6
35	610	323	9716	6802	103.5	1422	2030	8	1.9
35	690	367	10870	7608	116.6	1804	2576	9	2.1
35	770	399	13042	9130	134	2382	3404	10	2.3
35	850	443	14190	9932	147.1	2870	4100	11	2.6
35	930	487	15338	10736	160.2	3404	4862	12	2.8
35	1010	519	17530	12272	177.6	4184	5978	13	3.1
35	1090	563	18674	13072	190.7	4824	6890	14	3.3
35	1170	607	19818	13874	203.8	5508	7868	15	3.6
35	1250	639	22024	15416	221.2	6490	9272	16	3.8
35	1330	683	23164	16214	234.3	7280	10400	17	4.1
35	1410	727	24306	17014	247.4	8116	11594	18	4.3
35	1490	759	26520	18564	264.8	9300	13286	19	4.5

VT-P43 · 23 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	Mx* [Nm]	My [Nm]	Mz [Nm]	No. of holes	Weight per rail [kg]
43	210	123	3190	2234	60.6	168	240	3	1.1
43	290	158	5744	4020	93.8	402	576	4	1.5
43	370	208	6754	4728	115.9	616	880	5	1.9
43	450	243	9380	6566	149.2	1018	1456	6	2.4
43	530	278	12078	8454	182.4	1524	2176	7	2.8
43	610	313	14822	10376	215.6	2128	3042	8	3.2
43	690	363	15726	11008	237.8	2588	3698	9	3.6
43	770	398	18464	12926	271	3362	4804	10	4
43	850	433	21230	14862	304.2	4238	6054	11	4.5
43	930	483	22108	15476	326.4	4878	6968	12	4.9
43	1010	518	24868	17408	359.6	5922	8460	13	5.3
43	1090	568	25754	18028	381.8	6674	9534	14	5.7
43	1170	603	28508	19956	415	7886	11266	15	6.1
43	1250	638	31276	21894	448.2	9198	13142	16	6.6
43	1330	688	32150	22504	470.4	10130	14472	17	7
43	1410	723	34912	24438	503.6	11612	16590	18	7.4
43	1490	758	37690	26382	536.8	13196	18850	19	7.8
43	1570	793	40476	28334	570.1	14880	21256	20	8.2
43	1650	843	41322	28926	592.2	16058	22940	21	8.7
43	1730	878	44104	30872	625.5	17912	25588	22	9.1
43	1810	928	44958	31472	647.6	19202	27432	23	9.5
43	1890	963	47734	33414	680.8	21224	30320	24	9.9
43	1970	1013	48596	34018	703	22628	32324	25	10.3

VT-P63 · 18 lengths

Size	Length L [mm]	Stroke H [mm]	C₀rad [N]	C₀ax [N]	Mx* [Nm]	My [Nm]	Mz [Nm]	No. of holes	Weight per rail [kg]
63	610	333	21182	14828	474	3106	4438	8	6.3
63	690	373	25068	17548	547.5	4144	5920	9	7.1
63	770	413	28978	20284	621	5332	7616	10	7.9
63	850	453	32904	23032	694.5	6668	9526	11	8.8
63	930	493	36842	25790	768	8154	11648	12	9.6
63	1010	533	40790	28554	841.4	9788	13984	13	10.4
63	1090	573	44746	31322	914.9	11574	16534	14	11.2
63	1170	613	48708	34096	988.4	13508	19296	15	12.1
63	1250	653	52674	36872	1061.9	15590	22272	16	12.9
63	1330	693	56644	39650	1135.4	17824	25462	17	13.7
63	1410	733	60618	42432	1208.9	20204	28864	18	14.5
63	1490	773	64594	45216	1282.4	22736	32480	19	15.3
63	1570	813	68574	48002	1355.9	25416	36310	20	16.2
63	1650	853	72554	50788	1429.4	28246	40352	21	17
63	1730	893	76536	53576	1502.8	31226	44608	22	17.8
63	1810	933	80522	56364	1576.3	34354	49078	23	18.6
63	1890	973	84506	59154	1649.8	37632	53760	24	19.5
63	1970	1013	88494	61946	1723.3	41060	58656	25	20.3

Part-number builder

VT-P 28 . 690 . 358 . N

Load & moments are per pair of rails; Mx* is per single rail.

Examples

VT-P35.770
VT-P28.690.358.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-P22	7.5 mm
VT-P28	9.5 mm
VT-P35	12 mm
VT-P43	15 mm
VT-P63	20 mm

Field	Meaning
VT-P	Series — partial extension
28	Size (22 / 28 / 35 / 43 / 63)
690	Rail length L [mm]
358	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

Extension≈ 50 %

Load basisper pair of rails

Peak C₀rad88.5 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

Heavy machine buildingConstruction technologyAutomotiveRailway rolling stockLogistics complexesFood-industry equipment

Explore the VT range

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

Specify your VT-P — 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.