HDH Square Block Heavy-Duty Ball Linear Guideway
DLY HD Square Guideway is a heavy-duty ball-type linear guideway mainly equipped with HDH square carriage blocks. Recirculating steel balls move between the block and rail raceways, providing smooth linear motion, high load capacity and stable guidance for machine tools and industrial automation equipment.
The HDH block has a compact square profile that requires less lateral mounting space than a flange block. It is suitable for machine slides, positioning axes and equipment structures where the block is mounted from the top.
HDH-CA is the standard-length square block, while HDH-HA uses a longer block body to provide higher load and moment capacity. The same HD ball guideway series also includes HDW flange blocks for wider mounting surfaces and more flexible bolt installation.
HDH Square Block Design
HDH is the square-block version of the DLY HD heavy-duty linear guideway series. Its narrower block width is useful when the equipment has limited lateral installation space or when the guide block must fit inside a compact machine slide.
The HD guideway uses recirculating steel balls rather than cylindrical rollers. The ball circulation structure supports high loads while maintaining smooth movement and relatively low motion resistance. It is different from the RD roller guideway, which is designed for applications requiring still higher rigidity and resistance to heavy cutting loads.
HDH-CA and HDH-HA square block structure and dimension symbols
HDH-CA and HDH-HA
| Model Type | Block Shape | Block Length | Load and Moment Capacity | Selection |
|---|---|---|---|---|
| HDH-CA | Square block | Standard length | Heavy-duty configuration for general machine axes | Choose when longitudinal installation space is limited and the applied moment is moderate. |
| HDH-HA | Long square block | Longer than CA | Higher load and pitch/yaw moment capacity than the same-size CA block | Choose for heavier loads, larger overhangs or higher moment requirements. |
HDH Dimensions
Dimension symbol definitions:
H = overall assembly height; H1 = rail mounting reference height; N = block side reference dimension; W = block width; B = transverse block mounting-hole spacing; B1 = block side margin; C = longitudinal block mounting-hole spacing; L1 = main block body length; L = overall block length; G = lubrication-end dimension; M×l = block mounting thread and effective depth; T = block mounting-related height; H2/H3 = local block heights; WR = rail width; HR = rail height; D = rail counterbore diameter; h = rail counterbore depth; d = rail through-hole diameter; P = rail mounting-hole pitch; E = distance from rail end to the first mounting hole.
Unit: mm.
| Model | H | H1 | N | W | B | B1 | C | L1 | L | G | M×l | T | H2 | H3 | WR | HR | D | h | d | P | E | Rail Bolt |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HDH15CA | 28 | 4.3 | 9.5 | 34 | 26 | 4 | 26 | 39.4 | 61.4 | 5.3 | M4×5 | 6 | 8.5 | 9.5 | 15 | 15 | 7.5 | 5.3 | 4.5 | 60 | 20 | M4×16 |
| HDH20CA | 30 | 4.6 | 12 | 44 | 32 | 6 | 36 | 50.5 | 77.5 | 12 | M5×6 | 8 | 6 | 7 | 20 | 17.5 | 9.5 | 8.5 | 6 | 60 | 20 | M5×16 |
| HDH20HA | 30 | 4.6 | 12 | 44 | 32 | 6 | 50 | 65.2 | 92.2 | 12 | M5×6 | 8 | 6 | 7 | 20 | 17.5 | 9.5 | 8.5 | 6 | 60 | 20 | M5×16 |
| HDH25CA | 40 | 5.5 | 12.5 | 48 | 35 | 6.5 | 35 | 58 | 84 | 12 | M6×8 | 8 | 10 | 13 | 23 | 22 | 11 | 9 | 7 | 60 | 20 | M6×20 |
| HDH25HA | 40 | 5.5 | 12.5 | 48 | 35 | 6.5 | 50 | 78.6 | 104.6 | 12 | M6×8 | 8 | 10 | 13 | 23 | 22 | 11 | 9 | 7 | 60 | 20 | M6×20 |
| HDH30CA | 45 | 6 | 16 | 60 | 40 | 10 | 40 | 70 | 97.4 | 12 | M8×10 | 8.5 | 9.5 | 13.8 | 28 | 26 | 14 | 12 | 9 | 80 | 20 | M8×25 |
| HDH30HA | 45 | 6 | 16 | 60 | 40 | 10 | 60 | 93 | 120.4 | 12 | M8×10 | 8.5 | 9.5 | 13.8 | 28 | 26 | 14 | 12 | 9 | 80 | 20 | M8×25 |
| HDH35CA | 55 | 7.5 | 18 | 70 | 50 | 10 | 50 | 80 | 112.4 | 12 | M8×12 | 10.2 | 16 | 19.6 | 34 | 29 | 14 | 12 | 9 | 80 | 20 | M8×25 |
| HDH35HA | 55 | 7.5 | 18 | 70 | 50 | 10 | 72 | 105.8 | 138.2 | 12 | M8×12 | 10.2 | 16 | 19.6 | 34 | 29 | 14 | 12 | 9 | 80 | 20 | M8×25 |
| HDH45CA | 70 | 9.5 | 20.5 | 86 | 60 | 13 | 60 | 97 | 139.4 | 12.9 | M10×17 | 16 | 18.5 | 30.5 | 45 | 38 | 20 | 17 | 14 | 105 | 22.5 | M12×35 |
| HDH45HA | 70 | 9.5 | 20.5 | 86 | 60 | 13 | 80 | 128.8 | 171.2 | 12.9 | M10×17 | 16 | 18.5 | 30.5 | 45 | 38 | 20 | 17 | 14 | 105 | 22.5 | M12×35 |
| HDH55CA | 80 | 13 | 23.5 | 100 | 75 | 12.5 | 75 | 117.7 | 166.7 | 12.9 | M12×18 | 17.5 | 22 | 29 | 53 | 44 | 23 | 20 | 16 | 120 | 30 | M14×45 |
| HDH55HA | 80 | 13 | 23.5 | 100 | 75 | 12.5 | 95 | 155.8 | 204.8 | 12.9 | M12×18 | 17.5 | 22 | 29 | 53 | 44 | 23 | 20 | 16 | 120 | 30 | M14×45 |
| HDH65CA | 90 | 15 | 31.5 | 126 | 76 | 25 | 70 | 144.2 | 200.2 | 12.9 | M16×20 | 25 | 15 | 15 | 63 | 53 | 26 | 22 | 18 | 150 | 35 | M16×50 |
| HDH65HA | 90 | 15 | 31.5 | 126 | 76 | 25 | 120 | 203.6 | 259.6 | 12.9 | M16×20 | 25 | 15 | 15 | 63 | 53 | 26 | 22 | 18 | 150 | 35 | M16×50 |
Load, Moment and Weight
Load and moment symbol definitions:
C = basic dynamic load rating; C0 = basic static load rating; MR = permissible static roll moment; MP = permissible static pitch moment; MY = permissible static yaw moment; W1 = block weight; W2 = rail weight per meter.
C and C0 are in kN; MR, MP and MY are in kN·m; W1 is in kg; W2 is in kg/m.
| Model | C | C0 | MR | MP | MY | W1 | W2 |
|---|---|---|---|---|---|---|---|
| HDH15CA | 11.38 | 25.31 | 0.17 | 0.15 | 0.15 | 0.18 | 1.45 |
| HDH20CA | 17.35 | 37.84 | 0.38 | 0.27 | 0.27 | 0.30 | 2.21 |
| HDH20HA | 21.18 | 48.84 | 0.48 | 0.47 | 0.47 | 0.39 | 2.21 |
| HDH25CA | 26.48 | 56.19 | 0.64 | 0.51 | 0.51 | 0.51 | 3.21 |
| HDH25HA | 32.75 | 76.00 | 0.87 | 0.88 | 0.88 | 0.69 | 3.21 |
| HDH30CA | 38.74 | 83.06 | 1.06 | 0.85 | 0.85 | 0.88 | 4.47 |
| HDH30HA | 47.27 | 110.13 | 1.40 | 1.47 | 1.47 | 1.16 | 4.47 |
| HDH35CA | 49.52 | 102.87 | 1.73 | 1.20 | 1.20 | 1.45 | 6.30 |
| HDH35HA | 60.21 | 136.31 | 2.29 | 2.08 | 2.08 | 1.92 | 6.30 |
| HDH45CA | 77.57 | 155.93 | 3.01 | 2.35 | 2.35 | 2.73 | 10.41 |
| HDH45HA | 94.54 | 207.12 | 4.00 | 4.07 | 4.07 | 3.61 | 10.41 |
| HDH55CA | 114.44 | 227.81 | 5.66 | 4.06 | 4.06 | 4.17 | 15.08 |
| HDH55HA | 139.35 | 301.26 | 7.49 | 7.01 | 7.01 | 5.49 | 15.08 |
| HDH65CA | 163.63 | 324.71 | 10.02 | 6.44 | 6.44 | 7.00 | 21.18 |
| HDH65HA | 208.36 | 457.15 | 14.15 | 11.12 | 11.12 | 9.82 | 21.18 |
Product Range
HDH square blocks are available in sizes 15, 20, 25, 30, 35, 45, 55 and 65. The CA version is available across the listed range, while HA long blocks are available from size 20 upward.
HDH square block linear guideways in different sizes
HDH and HDW Block Options
HDH and HDW use the same HD ball-type guideway concept but have different carriage profiles. HDH is the main square-block option on this page. HDW is a flange block with a wider mounting surface and additional mounting arrangements.
| Item | HDH Square Block | HDW Flange Block |
|---|---|---|
| Block profile | Compact square profile | Wide flange profile |
| Main models | HDH-CA, HDH-HA | HDW-CA, HDW-HA, HDW-CB, HDW-HB |
| Mounting width | Narrower block width | Wider mounting surface |
| Installation | Primarily mounted through the top of the block | A- and B-type mounting-hole arrangements are available |
| Suitable layout | Compact slides and equipment with limited lateral space | Wide tables, frames and mounting plates |
HDW-CA and HDW-HA flange block dimensions
HDW-CB and HDW-HB alternative mounting arrangement
| HDW Model | Length Type | Mounting Arrangement | Selection |
|---|---|---|---|
| HDW-CA | Standard length | A-type flange mounting | General flange-block installation |
| HDW-HA | Long block | A-type flange mounting | Higher load and moment capacity |
| HDW-CB | Standard length | B-type flange mounting | Alternative bolt insertion direction |
| HDW-HB | Long block | B-type flange mounting | Alternative mounting with higher load and moment capacity |
Structure and Protection
The HD carriage block consists of the block body, recirculating balls, end caps, retainers, seals and lubrication components.
Rolling circulation system: block, rail, steel balls, end caps and retainers.
Lubrication system: grease nipple and lubrication passages.
Dust protection: end seals, bottom seals and rail bolt caps.
The retainer helps keep the balls inside the carriage when an interchangeable-type block is carefully removed from the rail.
Product Features
Heavy-Duty Ball Circulation
Recirculating steel balls support high loads while maintaining smooth linear movement and lower motion resistance than a sliding guide structure.
Four-Direction Load Support
The four-row raceway arrangement supports radial, reverse-radial and lateral loads, allowing the guideway to be used in different mounting orientations.
Compact Square Block
The HDH block is narrower than the corresponding HDW flange block, making it suitable for compact machine axes and restricted lateral space.
CA and HA Selection
CA provides a shorter block body, while HA increases block length, load rating and pitch/yaw moment capacity.
Controlled Interchangeability
Interchangeable-type blocks and rails should only be combined when the series, size, accuracy class and compatible preload specification match.
Identification Options
Product models and customer logos can be marked on blocks and rails when identification or customized branding is required.
Model marking and logo customization on an HDH carriage and rail
HD Ball Guideway and RD Roller Guideway
Both HD and RD are intended for demanding industrial motion systems, but they use different rolling elements. HD uses balls and provides a balanced combination of load capacity, smooth motion and installation adaptability. RD uses rollers and is selected when the application requires higher rigidity or stronger resistance to elastic deformation.
| Item | HD Ball Guideway | RD Roller Guideway |
|---|---|---|
| Rolling element | Recirculating steel balls | Recirculating rollers |
| Load capacity | High | Higher under comparable conditions |
| Rigidity | High | Higher |
| Running behavior | Smooth motion with relatively low resistance | Greater resistance to elastic deformation |
| Mounting requirement | Suitable for general precision mounting surfaces | More demanding mounting-surface accuracy |
| Typical selection | CNC axes, automation, packaging and general heavy-duty machinery | Heavy cutting, large machine tools and high-rigidity axes |
For a broader comparison of heavy-load guideway options, see the DLY Heavy Load Linear Guide selection page.
Applications
| Equipment | Typical Motion | Why HDH Is Used |
|---|---|---|
| CNC machine tools | Feed axes, worktables and spindle-head movement | High load capacity, rigidity and compact block width |
| Machining centers | X, Y and Z axis guidance | Stable guidance under machining loads |
| Grinding and cutting equipment | Grinding-wheel frames, worktables and cutting-head movement | Smooth motion and resistance to changing loads |
| Industrial automation | Transfer, assembly and positioning axes | Repeatable movement and flexible size selection |
| Packaging machinery | Pick-and-place, sealing and labeling mechanisms | Stable reciprocating motion under continuous operation |
| Battery and photovoltaic equipment | Alignment, conveying, coating and inspection stages | Load support with controlled linear positioning |
| Measuring and inspection equipment | Stage, sensor and camera movement | Smooth guidance when the selected accuracy and preload match the application |
Selection Notes
Choose the size according to the calculated load, required service life and applied static moments.
Choose CA or HA according to available longitudinal space and moment requirements.
Choose HDH or HDW according to block profile, mounting width and bolt-access requirements.
Choose HD or RD according to required rigidity, heavy-cutting load and mounting-surface accuracy.
Confirm accuracy and preload before ordering, especially when blocks and rails are supplied separately.
FAQ
Q: Is the HD guideway a ball-type or roller-type linear guide?
A: HD is a ball-type heavy-duty linear guideway using recirculating steel balls. DLY RD is the roller-type guideway.
Q: What is the difference between HDH-CA and HDH-HA?
A: HDH-CA has a standard-length square block. HDH-HA has a longer block body and provides higher dynamic load, static load and pitch/yaw moment capacity than the same-size CA model.
Q: What is the difference between HDH and HDW?
A: HDH is a compact square block mainly mounted from the top. HDW is a wider flange block with A- and B-type mounting arrangements. The choice mainly depends on installation width, mounting surface and bolt access.
Q: Can an HDH block be replaced with an HDW block of the same size?
A: The rail profile may be shared within a compatible HD size, but HDH and HDW have different block widths, assembly heights and mounting dimensions. The equipment mounting surface must be checked before changing the block type.
Q: Are HD blocks and rails interchangeable?
A: Only interchangeable-type blocks and rails with the same series, size, accuracy class and compatible preload specification should be combined. Confirm the complete model before ordering replacement components.
Q: When should an RD roller guideway be selected instead?
A: RD is more suitable when the machine requires higher rigidity, stronger resistance to elastic deformation or support for heavy cutting and impact loads. Its mounting surface generally requires more careful machining and alignment.
Need Help Selecting an HD Linear Guideway?
Send the required load, stroke, installation space, accuracy, preload and mounting arrangement for model confirmation.
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