bore honing · hillsborough, new jersey
Our bore honing services take internal bores to size, roundness and surface finish. Tolerances are held to ±.0001″, and finishes run from 32 RMS down to 4-8 RMS where a seal or a running fit needs it. Our Sunnen machines cover bores from .060″ up to 26″ diameter, and tube lengths to 120″.
Honing cuts with rotating stones rather than a single point, which is what lets it correct the bore rather than follow it. Taper, out-of-roundness and bell-mouth come out; size and finish come in. Nothing else leaves a bore that straight and that smooth.
Industrial cylinder honing is the bulk of it — hydraulic cylinders and cylinder tubes, sleeves, bushings and housings — along with any part that has a bore which has to seal, slide or run true. We have honed aircraft components and landing gear parts as well.
Most machine shops send their honing out, which adds weeks and another set of hands to the job. Here the hones sit on the same floor as the lathes and mills, so there are two ways to work with us.
Complete parts. We source the material, machine the part and hone the bore, with heat treating sent to our outside vendor in between. The part comes back to you finished and ready for assembly.
Finishing only. Already have the part machined? Send it in and we hone the bore to size, roundness and finish.
Deep holes are gundrilled here to 4″ diameter and 96″ deep, then honed on the same site. The part does not move between shops, and the bore ends up straight and finished.
Most of the honing that comes through here is from plants in New Jersey and across the northeast. The shop is in Hillsborough, in Somerset County, an easy drive from anywhere in the state and from the industrial corridor through Newark, Elizabeth, Jersey City and Paterson.
Cylinder tubes, sleeves and shafts travel well on a truck, so we take honing work from well beyond that. Send the part and the print and we will tell you straight whether the bore is ours.
Bore honing on the shop floor. Click to play the video.
Honing a 30 lb head cylinder for a blow molding machine.
Steel cylinder honed to its finished bore size.
Bore honing on cylinders and bushings at Zala Machine Co. — finishing bores to size, roundness and surface finish after boring.
Cylinder bore honed with coolant on the honing machine.
Mirror finish inside a honed bronze bore.
Bronze bushings with honed bores after finishing.
Five Sunnen machines cover small bores, programmable vertical honing and long tubes.
Bores from .060″ to 2.0″ diameter, 10″ long. The machine for the smallest bores.
Bores from 3/4″ to 2″ diameter, 16″ long.
Bores from 1/2″ to 18″ diameter, 12″ long.
IDs from 1/2″ to 26″, up to 120″ long. Long tubes, pipes and cylinder barrels.
Every honed bore is checked with bore gauges and ID mics before it leaves, and finish is verified on a profilometer.
Melt pipes and long-neck elbows are work this shop is set up for. The bore has to be straight, round and smooth enough that polymer moves through it without hanging up, and getting there means gundrilling the hole and honing it afterwards. Both happen here, on the same floor, so the part keeps its reference from one operation to the next.
We have made melt pipes and elbows for the major extruder OEMs for years — down-the-line polymer transfer — and we still do. It is a line of work we know from the inside, and one we are glad to take more of.
Hollow honed shafts are the same discipline. A deep hole drilled on centre, then honed to size and finish so the bore runs true to the outside diameter. See our melt pipe, elbow and honed tube work, or the rest of our extruder components.
The full machine list is on our facility list.
From .060″ up to 26″ diameter, and tube lengths to 120″. Four Sunnen machines cover that range: an MBB 1660 for the smallest work, two MBB 1803s, an SV-10 vertical programmable hone to 18″ diameter, and an HTH4000 tube hone for the long bores.
Internal diameters are held to ±.0001″. Finishes run from 32 RMS where heavy lubrication is wanted down to 4-8 RMS for a high-pressure seal. We set the finish to what the print calls for, not to a house default.
Yes. Industrial cylinder honing is the bulk of the work here — cylinder tubes, sleeves, bushings and housings. Bring the tube or the complete cylinder.
Yes, and a good share of our honing is exactly that. Send the part and the print. We correct taper, out-of-roundness and bell-mouth and bring the bore to size and finish.
Boring cuts the bore with a single point and follows whatever is already there. Honing cuts with rotating stones spread around the bore, so it corrects the geometry as it goes — that is what takes taper and out-of-roundness out. ID grinding holds size but will not leave the crosshatch that a running bore or a seal needs.
Yes. Deep holes are gundrilled here to 4″ diameter and 96″ deep, then honed on the same site. The part does not move between shops, and the bore ends up straight and finished.
Carbon and alloy steels, 4140 HT, stainless including 15-5 PH, Inconel, bronze and cast iron among others.
The shop is in Hillsborough, New Jersey, in Somerset County, an easy drive from anywhere in the state and from the industrial corridor through Newark, Elizabeth and Jersey City. We take honing work from across the northeast and further afield — cylinder tubes travel well on a truck.
Most honed parts are turned, milled or gundrilled here first. These pages cover that work.
Send us a part to finish, or let us make the whole thing. Because the honing machines sit alongside the lathes and mills, a bore that needs correcting does not leave the building, wait in another shop’s queue, or come back with a surprise. We hold the schedule either way.
Call the shop or email sales@zalamachine.com, or use the quote form below.
