zenithal angle of hole

This paper analyses that tip angle of drill bit influences on cutting capability and life of twist drill, when the material and shape of work piece is different.

分析了工件材料、形状不同时 ,钻尖顶角的大小对麻花钻切削性能及寿命的影响 ,介绍了麻花钻的钻尖顶角的选择 。

High position bores and elevation bores methane drainage technique can prevent gas problem successfully.

采用高位钻孔和仰角钻孔抽放瓦斯技术,有效地防止了瓦斯超限。

Application of Technology of High Gas Cannon Picking Roof Perforate Gas Administer

高瓦斯炮放面顶板钻孔法瓦斯治理技术应用

Technology of 1000 meter directional borehole at large diameter for mine gas extraction

顶板大直径千米长钻孔抽采瓦斯技术

Pressure releasing and gas drainage with long bore hole in roof overburden of fully mechanized caving face

综放面顶板覆岩走向长钻孔卸压抽放瓦斯研究

Fire Prevention Practice on Drilling Holes with Inclined Slices on Fully Mechanized Face Roof of Thick Seams in Junde Colliery

峻德矿特厚煤层综放面顶板下斜钻孔防火实践

Application of Gas Drainage in Fractured Zone by Roof High-level Boreholes in Daping Coal Mine

顶板高位钻孔裂隙带抽放在大平矿的应用

Gas drainage technique by 1000 m long and large diameter roof boreholes in high gas coal seam group

高瓦斯煤层群顶板大直径千米钻孔抽采技术

Drill a 12-mm (1/8-in) diameter hole in the top center of the fan shrou

在风扇围板顶部中心钻一个直径12毫米（1/8英寸）的孔。

The Study on the Key Gas Drainage Technique by Long & large Diameter Roof Boreholes in Fully Mechanized Face

综采面顶板走向大直径长钻孔瓦斯抽采技术参数的研究

dowelling in the length, of coniferous wood

针叶树木板,经纵钻孔的

They were drilling Boles in a steel plate

他们在钢板上钻孔。

They drilled through a Board

他们在木板上钻孔。

I drilled the board through.

我把木板钻了一个孔。

He bored a hole through a board with a drill.

他用钻在板上钻了一个孔。

The worker bored a hole through the board.

工人在木板上钻了一个孔。

Drill three holes in the floor/base plate for anchoring the leg.

在地面/底板上为锚固支柱打钻三个孔。

Advanced Drilling Technology of Micro-Via in PCB

印制电路板超细微钻孔先进加工技术

The Design on the Activities Template Drilling and Tapping Modular Machine Tool

活动模板式钻孔与攻丝组合机床设计

Distribution Features of Borehole Temperatures in the Miaoergou Flat-topped Glacier,East Tianshan Mountains

东天山庙儿沟平顶冰川钻孔温度分布特征